|
|
Joined: Jan 2001
Posts: 13,858
Carpal Tunnel
|
OP
Carpal Tunnel
Joined: Jan 2001
Posts: 13,858 |
Tonight in BBC News Sci-Tech there was a word new to me, about danger threatening areas near West Coast volcanos. Mudslides caused the most extensive damage to property from Mt.Saint Helens eruption. Their technical name it turns out is "lahar" which I had never seen before. Perhaps it would be interesting to have contributions for other uncommon words on this subject that may show up in news. wwh
|
|
|
|
|
Joined: Mar 2000
Posts: 11,613
Carpal Tunnel
|
|
Carpal Tunnel
Joined: Mar 2000
Posts: 11,613 |
Scree is pretty uncommon. Shoot, there's a name for the particulate that falls during and after an eruption, and I
can't think of it. Max would know.
|
|
|
|
|
Joined: Aug 2000
Posts: 3,409
Carpal Tunnel
|
|
Carpal Tunnel
Joined: Aug 2000
Posts: 3,409 |
Shoot, there's a name for the particulate that falls during and after an eruption, and I can't think of it. Max would know.
hot stuff
|
|
|
|
|
Joined: Nov 2000
Posts: 3,146
Carpal Tunnel
|
|
Carpal Tunnel
Joined: Nov 2000
Posts: 3,146 |
A lahar occurs when a lake in the crater of an active volcano overflows or the mountain erupts. They're a mixture of water, ice and volcanic debris. Lahars are pretty diabolical, because they generally happen when no one's particularly looking for them (being at the tops of mountains an' all). One occurred on Mt Ruapehu in 1953, swept down the mountain and destroyed the main trunk railway bridge at Tangiwai between Waiouru and Ohakune a few minutes before the daily express between Wellington and Auckland crossed it. A lot of people died. There's now a lahar warning system on Mt Ruapehu. If you're interested, this link will show you what's what! http://www.learnz.org.nz/2k/tongariro/t_lahars.htmScree is common enough here, Jackie. It occurs on the majority of the mountains in the Southern Alps which are mostly made up of greywacke rock. Scree is loose rock and gravel in a continuous slow landslide. Crossing it carelessly is one of the most common causes of injuries to hikers here in NZ. I got caught in a scree slide some years ago which was set off by the guy I was hiking with. It carried me about 20 metres and then "ran out" on a shallower slope below. But there could just as easily have been a bluff below me and then it would have been "good night all!" For some strange reason I wasn't very polite to him in spite of the fact it was just an inadvertent misstep on his part.
The idiot also known as Capfka ...
|
|
|
|
|
Joined: Mar 2000
Posts: 11,613
Carpal Tunnel
|
|
Carpal Tunnel
Joined: Mar 2000
Posts: 11,613 |
I think the word I was looking for was tephra. It was in C.K.'s link--thank you. I sicced Atomica on it. Atomica
didn't have it, and switched over and google-searched on its own! Thanks again, Jazz-o.
And, oh, C.K.--I meant that the word scree is not in common usage. I am very glad you're still with us.
|
|
|
|
|
Joined: Apr 2000
Posts: 3,065
Carpal Tunnel
|
|
Carpal Tunnel
Joined: Apr 2000
Posts: 3,065 |
Lahar is one of the contributions of Javanese to the English language. Others are batik and gong.
Bingley
Bingley
|
|
|
|
|
Joined: Jul 2000
Posts: 3,467
Carpal Tunnel
|
|
Carpal Tunnel
Joined: Jul 2000
Posts: 3,467 |
>Shoot, there's a name for the particulate that falls during and after an eruption, and I can't think of it. Max would know.
>hot stuff
This IS a family chat area. Please refer to Jackie by more acceptable terms :)
TEd
|
|
|
|
|
Joined: Mar 2000
Posts: 11,613
Carpal Tunnel
|
|
Carpal Tunnel
Joined: Mar 2000
Posts: 11,613 |
hot stuff... Thanks, Ted. The gutter hath a new king! 
|
|
|
|
|
Joined: Dec 2000
Posts: 393
enthusiast
|
|
enthusiast
Joined: Dec 2000
Posts: 393 |
Volcanoes give us aa and pahoehoe, not to mention tufa and tuff, and pyroclastic flow.
|
|
|
|
|
Joined: Oct 2000
Posts: 5,400
Carpal Tunnel
|
|
Carpal Tunnel
Joined: Oct 2000
Posts: 5,400 |
Jackie, i think scree is pretty common up and down Appalalain's-- and i know it also exist in Rockies-- same sort of factured shale-- most of the scree i've seen has been slag heaps (I paid good money to take a tour of a coal mine, and afterwards when fosile hunting-- they took us to a slag heap of shale, and let us climb up, and slip down the scree while hunting-- but i got some good fosiles!)
We also got to see a great example of a syncline and anticline-- geologist are fun--
Their names for things show even they have trouble remembering what's what.
Like:
Syncline's point down-- to the place sinners might end up--
Anticlines go up
These words are used to define the corregated like folds in rocks-- They are commonly seen in mountainous areas, and US east coast (very old, very eroded mountain range) has some great examples. In new mountain ranges they are often not as visible.
and
stalactites (stay up on the roof of a cave---glued on tight!) and stalacmites.
One of NY geologist-- Sydney Horstein-- has a little ditty about NY geology
Manhattan is schist
The Bronx is gneiss,
and NY is not with out its faults!
(it is common to intentionally mispronounce schist)
It not much-- but we've had 2 earthquakes in the past 2 months-- both in the 2's (2.5 and 2.9--i think) one on Manhattan's east side (felt 30 mile away) and one in lower Connecticut, and Ohio had one too.
|
|
|
|
|
Joined: Aug 2000
Posts: 3,409
Carpal Tunnel
|
|
Carpal Tunnel
Joined: Aug 2000
Posts: 3,409 |
we've had 2 earthquakes in the past 2 months-- both in the 2's (2.5 and 2.9--i think)
2s? Did you feel either of them? Anything less than 4.5 wouldn't even be noticed here, and I know people who have slept through 5s. My Dad was driving around town during our last signifcant shake, 6.4, and when he got home and was asked about the quake, he replied "what quake?"
|
|
|
|
|
Joined: Sep 2000
Posts: 347
enthusiast
|
|
enthusiast
Joined: Sep 2000
Posts: 347 |
>My Dad was driving around town during our last significant shake, 6.4, and when he got home and was asked about the quake, he replied "what quake?"
I had a car like that once too, Max.
|
|
|
|
|
Joined: Sep 2001
Posts: 6,296
Carpal Tunnel
|
|
Carpal Tunnel
Joined: Sep 2001
Posts: 6,296 |
I've spent the morning viewing clips of lahar on a site below someone posted above, I think; if not, someone posted the link somewhere in a thread related to lahar. To the point, I searched out some pyroclastic terms that may be of interest to those interested in volcanoes. Many that I found I'll omit in deference to those who won't want an unusually long post: pyroclast-- Volcanology. an individual particle or fragment of clastic rock material of any size that is formed by volcanic explosion or ejected from a volcanic vent.
http://www.harcourt.com/dictionary/def/8/3/1/4/8314100.html
pyroclastic ground surge Volcanology. the comparatively thin layer of rock of varying thickness found around a volcanic vent.
http://www.harcourt.com/dictionary/def/8/3/1/4/8314400.html
pyrogenesis Geology. 1. the intrusion and extrusion of a magma. 2. the products derived from a magma.the products derived from a magma.
http://www.harcourt.com/dictionary/def/8/3/1/5/8315400.html
pyroschist Petrology. a schist or shale with sufficient carbon to burn with a bright flame or to yield volatile hydrocarbons upon heating.
http://www.harcourt.com/dictionary/def/8/3/1/8/8318600.html
...now if I could just relocate the site that had the eerie photographs of pillow lava...
Oh, and here's the site that has the footage of lahar in action:
http://www.geo.mtu.edu/volcanoes/pinatubo/lahar/
WW
|
|
|
|
|
Joined: Nov 2000
Posts: 3,439
Carpal Tunnel
|
|
Carpal Tunnel
Joined: Nov 2000
Posts: 3,439 |
Volcanoes give us aa and pahoehoe
Two Hawaiian words. a'a is pronounced "ah-ah" and pahoehoe is Pah-HOY-hoy ... just in case anyone cares!
|
|
|
|
|
Joined: Nov 2000
Posts: 866
old hand
|
|
old hand
Joined: Nov 2000
Posts: 866 |
a'a allegedly got its name from the sound made when the Hawaiins walked barefoot across an a'a flow. I kid you not.
stales
|
|
|
|
|
Joined: Nov 2000
Posts: 866
old hand
|
|
old hand
Joined: Nov 2000
Posts: 866 |
wwh - there you go - right there - in the subject of this post....
We British Commonwealthers say 'geological'.
This spelling would make sense to Mr Spock (follow me on this one.........)
stales
|
|
|
|
|
Joined: Nov 2000
Posts: 866
old hand
|
|
old hand
Joined: Nov 2000
Posts: 866 |
A couple of my favourites relate to glacial deposits.
Picture if you will, a glacier slowly melting - dumping its load of boulders and bits of rock all along its path, not just at its end (for the geologically inclined - not at its 'terminal morraine'). Occassionally a large boulder will drop where no other large boulders are to be found. Once the glacier has melted one is left with a flat terrain with large boulders scattered here and there. Perhaps the most common technical term used for these is "erratic blocks".
Unfortunately Dr Robin Wass at Sydney Uni in 1978 ruined my geological and political correctness for all time. His pet term was the spooneristic, "erotic blacks". Ever since, I've really had to concentrate in order to use the correct term.
Another term for these isolated boulders (some the size of a house) is "knockers".
Once, when attending a presentation on the geology of Greenland (where knockers are a regular feature), I couldn't help myself. Just had to put up my hand and ask of the presenter, "Dr Ridley - could you comment upon whether there is any cleavage associated with those knockers?"
A rock unit's cleavage (as opposed to a crystal's cleavage) is an important component that assists geologists establish the structural history of the area).
stales
|
|
|
|
|
Joined: Apr 2000
Posts: 3,065
Carpal Tunnel
|
|
Carpal Tunnel
Joined: Apr 2000
Posts: 3,065 |
Stales, don't leave us hanging over your cleavage. What was Dr. Ridley's reply?
Bingley
Bingley
|
|
|
|
|
Joined: Dec 2000
Posts: 13,803
Carpal Tunnel
|
|
Carpal Tunnel
Joined: Dec 2000
Posts: 13,803 |
you could almost feel it.
Anything less than 4.5 wouldn't even be noticed here
Whether one notices an earthquake depends not only on the Richter Scale level but also on the nature of the ground through which the shock waves are travelling. Earthquakes felt through the suspension of an automobile can be mistaken for shock waves from passing trucks.
|
|
|
|
|
Joined: Sep 2001
Posts: 6,296
Carpal Tunnel
|
|
Carpal Tunnel
Joined: Sep 2001
Posts: 6,296 |
Stales...You wrote:
A rock unit's cleavage (as opposed to a crystal's cleavage) is an important component that assists geologists establish the structural history of the area).
Crytal's cleavage isn't important to geologists?
And, on geologic and Dr. Spock: Would he prefer biologic, psychologic, anthropologic, and gang?
DubDub
|
|
|
|
|
Joined: Dec 2000
Posts: 13,803
Carpal Tunnel
|
|
Carpal Tunnel
Joined: Dec 2000
Posts: 13,803 |
Crystal's cleavage isn't important to geologists?
Well, maybe it is, maybe it isn't but I doubt if it is an important component that assists geologists establish the structural history of the area.
|
|
|
|
|
Joined: Oct 2000
Posts: 5,400
Carpal Tunnel
|
|
Carpal Tunnel
Joined: Oct 2000
Posts: 5,400 |
interstesting stales-- i have heard these odd boulders called glacial erratics .
there are some famous ones locally ..On Long island, Shelter Rock, give its name to a town and road.. in the bronx, in the Bronx zoo "the rocking stone" and other rocking stone in westerchester county. Faldage, do you kniow of any? I can't think that there would be three i know.. and none up your way..
both of the rocking stones are huge-- the bronx one is a over 2 meters on each side, (it it more a less a cube..) and it sits on an outcropping of gniess.. and if touch, and pushed at just the right point, it will move an inch or two, fall back, and rock back and forth a few times..
its well know.. and when the zoo expanded, special care was taken not to disturb it. it sits just outside the World of Darkness building.. the second one, is harder to rock.. and is less than a mile from the Cross county shopping center.. everytime some one wants to develop the land its sits on, local geologists, native americans and general NIMBY's get up in arms and demand it be preserved.. so far, they have won.
glacial erratics in souther michigan pointed explorers to look for copper in norther MI, many of them had copper.. some geologist think that there are richer copper deposits in canada, and that the copper bearing rocks are from further north still..
|
|
|
|
|
Joined: Jan 2001
Posts: 13,858
Carpal Tunnel
|
|
OP
Carpal Tunnel
Joined: Jan 2001
Posts: 13,858 |
"Crystal's cleavage isn't important to geologists?" Show us a picture of Crystal!
|
|
|
|
|
Joined: Nov 2000
Posts: 866
old hand
|
|
old hand
Joined: Nov 2000
Posts: 866 |
Bingley - I'm afraid Dr Ridley's reply was lost in the hubbub I caused. His smirk said it all though!
stales
|
|
|
|
|
Joined: Nov 2000
Posts: 866
old hand
|
|
old hand
Joined: Nov 2000
Posts: 866 |
ww...
We're not just splitting hairs here (hehehehe)
The cleavage of a particular crystal or a type of mineral is critically important to a gemmologist - as opposed to a geologist. This property, along with lustre/er, streak, hardness, transparency etc is what contributes to whether a mineral makes a good gem - or how it should be used as a gem - ie should it be faceted or cabochoned frinstance. (A soft mineral or one that fractures easily will not last long if used in jewellery).
The cleavage of a rock unit however, when looked at in conjunction with its jointing, folding and/or faulting, enables a structural geologist to work out the stress and strain regime required to bring about the deformation. This assists them in working out the the geologicAL history of the district. This enables them to write learned papers, the volume of which is directly proportional to their future scholarship and departmental funding - as well as the likelihood of them attaining a professorial appointment. Occassionally their findings receive application in the real world however, when "proper" geologists - ie exploration geologists - use the information to explain why an economic mineral deposit was found where it was. It's important to note that the learned papers are always written AFTER the deposit has been found - they are NEVER instrumental in the ore body being found. (BTW - this is my first 'white bit' - how'd I go?
Naturally enough, these macro-scale events are usually seen at the micro-scale - ie the rocks' constituent grains are also deformed. Too much deformation would negate their value as a gem.
Now, did I get enough four syllable words in? Very important part of geo-speak those four syllable words. "Phreatomagmatic" is a beauty - it's got six!! Got the taste for white bits now!!
stales
|
|
|
|
|
Joined: Sep 2001
Posts: 6,296
Carpal Tunnel
|
|
Carpal Tunnel
Joined: Sep 2001
Posts: 6,296 |
Fascinating reading, Stales, and your white's all white!!
We have some huge boulders out here in Dinwiddie County, Virginia, that my Uncle LL says were left by the the glaciers. It's a fantasy of mine to go traipsing about the countryside with a geologist to get the big view of how things rocky settled down here.
By the way, a geologist, a Dr. Walz from VCU, visited our school last year. He had lots of big rock samples. I talked to him briefly before his demonstration for our fourth graders about his samples. I asked which was the oldest in his collection as I eyed some whoppers that looked really hard and old. I was surprised when he lifted a big chunk of slate and said, "This one is four billion years old." I was surprised because the slate looked, I dunno, least old--something more frangible than the others. If I had two more lifetimes to live the first would be to study dendrology; the second would be to study geology. You're in a great field.
Best regards,
WW
|
|
|
|
|
Joined: Nov 2000
Posts: 866
old hand
|
|
old hand
Joined: Nov 2000
Posts: 866 |
dubya squared Show me a kid that's not fascinated by rocks..... I think something happens during the teen years where more pragmatic likes take over. I used to sell mineral specimens - many of which went into small, sweaty, sticky hands in exchange for the 50 cent piece their parents had given them to spend at the show. For interest's sake, the oldest rocks in the world have been found at the "Jack Hills" in the Kimberley District of far northern Western Australia. (So I am not the only fossil in WA!) The tiny zircon crystals were identified and dated by a guy I went to university with - Peter Kinny - aka Skinny Pete. Dated at 4.4 billion years, it is more technically correct to refer to "the oldest rock grains". This is because the rock they were found in is a metamorphosed sediment - and therefore the original rock that contained the zircons has been weathered away, releasing them. What I'm trying to say is that the zircon grains actually predate the rock they are now in - but it still stands that these are the oldest rock units on the planet. The following URL provides an easy to understand collation of old rocks. Its logo is the actual zircon grain ID'd by Skinny Pete and the crew at Curtin University, Perth. There's also a few photos of the Jack Hills area - some pretty tough country. I wonder if this was where Dr Walz got his specimen? (ie did he go Walzing Matilda through the Aussie outback?) http://www.geology.wisc.edu/zircon/Earliest Piece/Earliest.htmlBTW - I got out of geology a few years ago - luckily. There's been wholesale unemployment since the Bre-X fiasco in 1997 and subsequent crash of commodity prices. Something like 1800 geologists now underemployed in Perth alone. Can't say I saw it coming - I just wanted to spend more time at home. stales
|
|
|
|
|
Joined: Sep 2001
Posts: 6,296
Carpal Tunnel
|
|
Carpal Tunnel
Joined: Sep 2001
Posts: 6,296 |
I enjoyed reading your link, wwh. The part about the crocodiles was most interesting: KILLER CROCS. In the jungles of South America, Golden Star Resources Ltd. has faced even more formidable obstacles. The Denver-based company, founded in 1984, is now one of the world's largest specialized exploration companies. Jaguars, wild hogs, and killer crocodiles lurk near the company's properties. Plate-size spiders eat birds, and malaria is a constant threat. Dealing with the locals can also prove challenging. When Golden Star CEO David A. Fennell met with tribal chiefs near one camp, ''they had a prayer to the gods that our geologists would have the eyes to see the gold,'' he recalls. He and his wife also went through a tribal wedding ceremony.and: Coming so soon after Bre-X, that may seem like dangerous advice. But gold rushes have always been fueled by people willing to take extraordinary risks. Few are likely to wade through the jungles of the Amazon, or venture to the mountains of Central Asia, unless they're possessed by intoxicating dreams combining greed, glory, and gold. It's a mix that can easily spin out of control. But at least for now, the potential rewards seem too great for prospectors with the deepest pockets and the steeliest nerves to pass up.http://www.businessweek.com/1997/20/b352798.htm(Your link again) "Greed, glory, and gold," not to mention green crocodiles lying in gluttonous wait...the ultimate lurkers. Best regards, WW
|
|
|
|
|
Joined: Sep 2001
Posts: 872
old hand
|
|
old hand
Joined: Sep 2001
Posts: 872 |
Two weeks ago I received an email from a geologist with the USGS, in part it read..."...if you can prove altitude clustering is non-stratigraphic, trying to keep the story in the second half of thr pleistocene opens a big can of worms, because the implications for subaerial fluvial geomorphology are fairly sweeping. ( Oh Baby, talk dirt to me, USGS; Say " subaerial fluvial geomorphology" for the nice man, Junior.) the sentence above in blue, as well as the rest the email was, to me, clear, precise, and written with great economy. Geology, unlike other disciplines such as the "dark art of lawyering", has taken care in developing concise referents for the words in it's lexicon. To some extent if you know the words you pretty well know the science.
But Geology's careful love affair with words is not surprising, three-thirds of the geologists of the world spent two-thirds of the last century naming things and looking for oil, while every schoolboy who had ever worked a picture puzzle could see that South America fit snugly with Africa. But even after "Plate Tectonics" I think it best not to reinforce too many neural links to the words "plumes", "hot spots", or even "plates". It may be years before Geologists know precisely what they mean.
Sometimes though, Geology ignores important questions that interests me. For example the " Carolina Bays." While they are neither restricted only to the Carolinas nor are they bays, the origin of 500,000 elliptical northwest trending lakes is largely ignored by geologists and so left to free thinkers to explain. I am personally torn between the "Mammoth Wallow Hole" theory and the "Exploding Comet".
One odd theory (Thom 1970) combines...wind deflation with perched water tables and shore erosion at a ninty degree angle to the prevailing wind. Maybe Wordwind, AWAD's own prevailing wind from the Carolinas has an opinion or knows the answer.
|
|
|
|
|
Joined: Sep 2001
Posts: 6,296
Carpal Tunnel
|
|
Carpal Tunnel
Joined: Sep 2001
Posts: 6,296 |
Hello, Milum...
This wind is from the Old Dominion, Virginia. I enjoyed reading your dirt, but was dumb as dirt understanding it. A Wind is, but knows not from whence it comes.
For example, when you wrote, "Mammoth Wallow Hole" theory and the "Exploding Comet", all I could see was some prehistoric beast doing a cannonball into the Tar Pits...
But back to basics: Which is the heaviest of the minerals? And the lightest? I think talc is the softest on the mohs scale and diamond, the hardest.
WordWacker
|
|
|
|
|
Joined: Nov 2000
Posts: 866
old hand
|
|
old hand
Joined: Nov 2000
Posts: 866 |
> Which is the heaviest of the minerals? And the lightest?
Great question dubdub!
I don't know if it's THE lightest (or, more correctly, that with the lowest specific gravity) but Evenkite would have to be right in there with a chance. It's SG of 0.87 (ie 0.87 grams per cubic centimetre) puts it in a class of its own in comparison to its nearest competitor (that I'm aware of) Sassolite (SG 1.45).
Evenkite is a rare mineral found only in the drainage area of the Tunguska River (former USSR) and at a couple of places in Czechoslovakia. It's a mixture of carbon and hydrogen (formula C24H50).
Mercury (the only liquid mineral at standard temperature and pressure) has the highest SG. At 13.6, it is also in a class of its own, the nearest competitor (Hessite - a silver telluride) has an SG of 8.4.
stales
|
|
|
|
|
Joined: Jan 2001
Posts: 13,858
Carpal Tunnel
|
|
OP
Carpal Tunnel
Joined: Jan 2001
Posts: 13,858 |
Dear Stales: I was surprised by your statement that Mercury had the highest specific gravity: 13.6 I found a site about minerals that says Gold has a specific gravity of 19.3 http://mineral.galleries.com/minerals/elements/gold/gold.htm
|
|
|
|
|
Joined: Aug 2001
Posts: 2,605
Carpal Tunnel
|
|
Carpal Tunnel
Joined: Aug 2001
Posts: 2,605 |
Without stopping to LIU, I believe that osmium is the densest of the elements, and that each of its closely-akin elements is also more dense than gold.
As to the lightest mineral: stales, your post would indicate that only one mineral will float in water -- correct? I believe pumice also floats, albeit for a different reason (trapped air).
|
|
|
|
|
Joined: Sep 2001
Posts: 6,296
Carpal Tunnel
|
|
Carpal Tunnel
Joined: Sep 2001
Posts: 6,296 |
How exciting! A triple heavyweight championship fight! In this corner, weighing in at 13.6 specific gravity, we have Mercury; in the opposite corner we have Gold, at 19.3; and, standing in between, we have Osmium at an indetermined weight, but he don't care! He's champing at the bit to knock ol' Feathershoes and Gildedlegs down!
The heavyweight championship prize? An evening out with cute little Evenkite, the airhead, who spends her time sunbathing on the shores of the Tunguska.
Bets regards,
WordWeight
|
|
|
|
|
Joined: Jan 2001
Posts: 13,858
Carpal Tunnel
|
|
OP
Carpal Tunnel
Joined: Jan 2001
Posts: 13,858 |
Dear Keiva: to document correctness of your reply:
Osmium discovered in 1804. Bluish white in colour. Specific gravity over
21. The heaviest metal known. Associated with Iridium in alloys. ...
http://www.nandesign.com/metals.htm
|
|
|
|
|
Joined: Aug 2001
Posts: 2,605
Carpal Tunnel
|
|
Carpal Tunnel
Joined: Aug 2001
Posts: 2,605 |
Edit, after LIU:: gold is well below the most dense element, but the sources conflict slightly on the details: http://www.science.co.il/PTelements.asp?s=Density ranks osmium as the densest element, closely followed by related elements iridium, platinum and rhenium. Gold is 8th (or 6th if the trans-uranium elements are excluded), slightly behind tungsten (a/k/a wolfram). Another source places iridium slighly above osmium, and places gold slightly above tungsten. http://www.webelements.com/webelements/elements/text/Os/phys.html (see graphic, click to adjust it to "shaded table" format, and then scan cursor over it for pop-ups)
|
|
|
|
|
Joined: Mar 2001
Posts: 4,189
Carpal Tunnel
|
|
Carpal Tunnel
Joined: Mar 2001
Posts: 4,189 |
For a fascinating look at Javanese volcanic sulphur mining in the new Smithsonian magazine click this link, and then click on Fire and Brimstone in the table of contents. There's also a great story for the paleontologically inclined, Whales on Mountains, about a fossil expedition to the Andes. The finds documented here help validate the theory that the Andes were among the fastest growing mountains in the world. These are, however, abstracts and not the full texts, but well worth a look anyway. http://www.smithsonianmag.si.edu/smithsonian/toccurrent.shtml
|
|
|
|
|
Joined: Nov 2000
Posts: 866
old hand
|
|
old hand
Joined: Nov 2000
Posts: 866 |
We need to differentiate between elements, minerals and rocks - otherwise comparing SG's becomes an apples and pears exercise.
Gold and osmium are both elements - ie they only consist of one chemical entity each. Gold is also regarded as a mineral however - belonging to the 'Native Element' class of most classification systems. I don't think Osmium is found on its own in nature - it is found in platinum ores and as part of the mineral now known as "Iridium" - which has an SG between 19.3 and 21.1, depending upon its composition. Iridium - the mineral - actually consists of several elements combined to a greater or lesser extent but with Iridium - the element - dominant. Either way, Mercury is not the heaviest mineral and I apologise for taking y'all on that voyage up the garden path.
Evenkite would float on water (because its SG is less than water's 1.0) - but I believe it dissolves readily, so this will have to remain as a thought experiment.
Pumice does float on water but, as you surmised, this is due to its physical structure. Furthermore, it is a rock type - rocks being made up of two or more minerals - though technically one could call a lump of talc (frinstance) "talc rock". Minerals are made up of one or more elements.
stales
|
|
|
|
|
Joined: Sep 2001
Posts: 6,296
Carpal Tunnel
|
|
Carpal Tunnel
Joined: Sep 2001
Posts: 6,296 |
Many thanks, Stales, for the clarification thus far. I've enjoyed the voyage up the garden path, and, being one who rarely sees the forrest for the trees, I didn't see the path for the rocks on it--or minerals in it...trying to be a passing student here.
So: Is gold, then, the heaviest mineral? Or is it Iridium (outweighing gold), even though Iridium pals up with other minerals? (I'm not trying to be dense as Iridium here.) And Evenkite is the lightest? If anything, it's been fun having my consciousness raised at least to recognizing what SG means, should I read it again, and understanding its meaning.
Heh! What's the Rock of Gibraltar composed of??? And the Blarney Stone??? I'll come back tomorrow and post a link to a terrific rock study that's going on in New York. Very impressive work they're getting out of those New Yorkers.
Best regards,
DubDub
P.S. Mebbe somebody could waterproof Evenkite with a substance that has an SG less than 1.0. You never know when there may be a need for floating Evenkite. Or change its physical structure so it'll float. Alert scientific minds can see though to future applications.... Evenkite Jet Skiis... used for strictly scientific research.
|
|
|
|
|
Joined: Nov 2000
Posts: 866
old hand
|
|
old hand
Joined: Nov 2000
Posts: 866 |
Evenkite - the mineral with the lowest SG that stales is aware of.
Mercury - mineral and native element - NOT the 'heaviest' of either. Any statement to the contrary is a stales furphy.
Gold - also a mineral and native element - also NOT the heaviest of either.
Osmium - an element (Os) - but not a mineral and not found in the elemental state in nature.
Iridium - Confusing. An element (Ir) - but not found in its elemental form in nature. A different beast, 'Iridium' (formerly known as Osmiridium) is a mineral with the formula (Ir,Os,Ro) - ie it's an alloy of three metallic elements, iridium, osmium and rhodium. Iridium (the mineral) IS the heaviest mineral that stales is aware of - having now been brought into line.
In the mineral world one always uses a leading capital letter when spelling the mineral species - thus usage would be: ....the heaviest of minerals is Iridium, which consists of iridium, osmium and rhodium.
Any other contenders or do we now have it?
stales
|
|
|
|
|
Joined: Apr 2000
Posts: 3,065
Carpal Tunnel
|
|
Carpal Tunnel
Joined: Apr 2000
Posts: 3,065 |
I've been there  . Ijen is in a very isolated part of East Java. I went there about 12 years ago to have a look at the volcano. To get there you go by bus to a town whose name I've forgotten now, and then hitch a ride in the back of a truck going to the Ijen coffee plantation. They don't let down the tail gate of the truck, you clamber in over it (I do not clamber easily). If I remember rightly we had a burst tyre on the way -- everybody clambers out while they fix the tyre and then clambers back in. There's a plantation guest house where you can stay for a couple of nights, with a few warungs (small shops)round about where you can buy bottled water, instant noodles, and snacks. Boiled peanuts are very popular. (You mean you eat them raw! Doesn't it give you a stomachache?)Excuse me a moment while I go and have a look at my photos. In the morning I went by ojek (motorcycle taxi) to the base of the mining camp. Kawah Ijen means Ijen Crater. It's in the foothills of a volcano called Merapi (very popular name for volcanoes -- just means firy). I had some good views of the volcano belching out smoke. The path to the crater goes up a steep ridge and then down into the crater itself. The vegetation either side of the path is mainly scrubland and conifers of one sort or another( pinus in Indonesian). I was reasonably fit in those days but I was definitely panting by the time I'd ambled my way up to the top -- and all I was carrying was a small backpack with a bottle of water and some sunscreen. It took me about an hour to get up but the miners trot up and down the path much faster than I was going and with a pikulan (long piece of wood with a big panier at each end) full of sulphur rocks (I don't know the specific gravity of sulphur but I'm sure they were pretty heavy). They certainly didn't seem to be showing any ill effects from this. In the crater itself they chip out the exposed sulphur rocks from the surface of the ground. There's a grey-green lake at the bottom of the lake which I didn't want to get too close to as it was giving off an unhealthy-looking steam. The water running down the sides of the crater was quite hot and smelt horrible, though it's recommended for skin complaints and the complexion, apparently. I did try washing my face in it, but can't say whether it had much effect! Smoke comes out of the ground in places and if the wind happens to be in the wrong direction you can get a lung full which is not very pleasant -- eyes and nose streaming and a terrible smell of something that has gone badly wrong with the drains. PS. Having been to Ijen makes me a veteran according to Anu. Bingley
Bingley
|
|
|
|
|
Joined: Mar 2000
Posts: 11,613
Carpal Tunnel
|
|
Carpal Tunnel
Joined: Mar 2000
Posts: 11,613 |
Hearty congratulations, veteran Bingley! 
|
|
|
|
|
Joined: Jun 2001
Posts: 2,636
Carpal Tunnel
|
|
Carpal Tunnel
Joined: Jun 2001
Posts: 2,636 |
I, too, have climbed a volcano. This was two years ago in Costa Rica. Volcán Arenal is an active volcano. When we arrived in the town, the top portion of the volcano was obscured by clouds. That afternoon we took an excursion(the only way I would reccomend climbing an active volcano) that led us through the forest and up the mountain. It started calmly enough. A nice walk through the forest. Then we reached a point where the path began to get steeper and slicker, due to obsidian-like sand. The final stretch was boulder-hopping at its finest. Each boulder had a rough, ground glass quality that would skin you alive if you slipped and fell. Quite the incentive to step carefully. Did I mention it was dark by then? When we reached the farthest point recommended for climbing, we were politely asked to not risk the Red Cross rescue teams that would have to go in and retrieve our bodies if we wished to get a closer look. The cloud cover was still holding and we could hear boulders smashing down the mountain. Occasionally the clouds would lift and we could see the lava shooting toward the sky. All in all, it was quite impressive. Our tour ended at the resort at the bottom of the mountain that had pools fed by hot springs and a swim up bar. Best way I know to ease the overworked muscles. Anyone contemplating a trip to Costa Rica should try it. I give it A 92.
|
|
|
|
|
Joined: Mar 2001
Posts: 4,189
Carpal Tunnel
|
|
Carpal Tunnel
Joined: Mar 2001
Posts: 4,189 |
Cool, Bingley! Thanks for the great first-hand account! From the accounts in the article and accompanying photos all I can say is that those miners are some mighty brave souls...and all for less than $2 a day! And using a sulphur mining process that was outdated in the 19th century!  And congrats on your other "elevation"!
|
|
|
|
|
Joined: Nov 2000
Posts: 866
old hand
|
|
old hand
Joined: Nov 2000
Posts: 866 |
Congratulations on reaching two dizzying pinnacles Bingley!
stales
PS - Thanx for the link to the Smithsonian article. The comment that those guys appear to be suffering no ill effects despite ten years working in the crater seems far fetched. Without proper filtration equipment the SO2 vapours they inhale will condense as sulfuric acid in their trachea and lungs. Having been exposed to only a couple of whiffs of sulfur dioxide from the old smelter at Kalgoorlie I can say first hand it's an unpleasant, let alone highly dangerous pastime. Asthmatics are particularly susceptible - likely to have a major attack within seconds.
|
|
|
|
|
Joined: Jul 2000
Posts: 3,467
Carpal Tunnel
|
|
Carpal Tunnel
Joined: Jul 2000
Posts: 3,467 |
stales:
Mercury does NOT appear in nature in its elemental form. It is so volatile in reaction that it turns into a compound (which is a molecule consisting of two or more different atoms) when "in the wild". The most common form is I believe cinnabar, one mercury atom coupled with one sulfur atom. It also oxidizes, and that's one thing Terra has is plenty of oxygen (even up here.)
TEd
TEd
|
|
|
|
|
Joined: Nov 2000
Posts: 866
old hand
|
|
old hand
Joined: Nov 2000
Posts: 866 |
Ted - sorry to have to contradict you - but....
Native Mercury is rare - but it is found at several places as Mercury, not Cinnibar. It occurs as tiny blobs embedded in crevices and pores of the rock and does not roll around unless tampered with. Locations include:
(1) The best specimens are found in association with Cinnibar at Almaden, Ciudad Real, Spain.
(2) The Almaden and New Almaden mines in Santa Clara county, California.
(3) The Socrates Mine, Sonoma County, California.
(4) At Idria, San Benito County, California.
(5) In Arkansas and Texas
(6) In Czechoslovakia
I stated earlier that it was the only liquid mineral at standard temperatures and pressures. Technically this is incorrect as Water also fills this bill. It belongs in the Oxides group - being an oxide of hydrogen.
stales
|
|
|
|
|
Joined: Sep 2001
Posts: 6,296
Carpal Tunnel
|
|
Carpal Tunnel
Joined: Sep 2001
Posts: 6,296 |
From the dense-as-iridium land of DubDub:
Stales, thanks for providing those pockets of Mercury. But you lost me when you made your point about mercury and water. Water's not a mineral, however, is it, so your point that mercury is the only liquid would appear to still stand on its liquideous little legs, huh? When you mentioned the oxides group, that was where you lost me in the discussion about minerals...
Thanks for your patience,
Rocky
PS: The Socrates Mine in Sonoma County, California, inspired me to ask still another question.
|
|
|
|
|
Joined: Nov 2000
Posts: 866
old hand
|
|
old hand
Joined: Nov 2000
Posts: 866 |
ww
I got the following info from a commercial site and would be happy to provide its URL via PM - just let me know. Under the definition provided, water IS a mineral.
"A mineral, by definition, is any naturally occurring, inorganic substance, often additionally characterized by an exact crystal structure. Its chemical structure can be exact, or can vary within limits. Elements that occur naturally are also considered minerals.
All minerals belong to a chemical group, which represents their affiliation with certain elements or compounds. The classified chemical groups are known as: Elements, Sulfides, Oxides, Halides, Carbonates, Nitrates, Borates, Sulfates, Chromates, Phosphates, Arsenates, Vanadates, Tungstates, molybdates, and Silicates. Some of these chemical groups have sub-categories, which may be categorized in some mineral references as separate groups.
All minerals belong to various crystal structure groups, classified according to the way the atoms of the mineral are arranged. Minerals also have distinctive properties, such as color, hardness, crystal habit, specific gravity, luster, fracture, and tenacity. Many of these properties can vary among a single mineral, within limits. Many minerals exhibit certain properties that others do not, such as fluorescence and radioactivity.
Minerals are an economic commodity; they are mined because of the need for a valuable element they contain or an intrinsic property they may have. Other minerals are mined for their beauty and rareness, thus giving many specimens an accepted worldwide value. There are about 3,000 different types of minerals, and new ones are constantly discovered. Most of them are not known to professional mineral collectors, because they are rare, have no economic purpose, and for the most part do not make good specimens."
I note also that there's a school of thought that seeks to use a separate category - "minaraloids". The definition given is that these substances are amorphous, inorganic that lack crystal structure. Along with Mercury, this group includes Water, Opal and Obsidian. I'm a traditionalist and prefer the KISS approach - mercury and water are minerals to me.
In classification terms Quartz is a trap for new players. Because people know it consists of silicon and oxygen they often mistake it for a silicate. In fact it also is an oxide - of silicon
stales
|
|
|
|
|
Joined: Apr 2000
Posts: 3,065
Carpal Tunnel
|
|
Carpal Tunnel
Joined: Apr 2000
Posts: 3,065 |
For those who want to see a volcano without actually having to climb up it, there is a drive-in volcano just outside Bandung called Tungkabun Prahu (meaning overturned boat). According to legend there was a beautiful queen in search of someone worthy to replace her beloved late husband. To make sure that the candidate was indeed worthy he had to build her a boat in a single night so that they could go sailing on the local lake. A handsome young stranger called Sangkuriang who had the gods on his side decided to have a go. He prayed to the gods to prevent the sun from rising until he'd finished his boatbuilding. When the queen came to see how he was getting on, she recognised by a scar on his shoulder that he was in fact her son who had been lost in the jungle as a child. In desperation she woke up a cockerel, which crowed and the sun came up. In a fit of temper the prince threw the boat he'd almost finished at the mountains. The boat broke one of the mountains which was damming up the lake so the lake drained away and the boat became a mountain in its place.
With a bit of imagination and from the right direction the mountain does look like an upside down Noah's ark. Some people say that the story is a folk memory of real geological events.
Anyway, be that as it may there is a road up to the lip of the volcano's crater so that you can go and have a look down into the volcano. Nothing very spectacular to see, just grey and yellow rocks and steam belching out in various places. The volcano did erupt in the 1970s but not much damage was done. There is a geyser where you can boil eggs, and a town in the valley below where you can bathe in hot springs. Very relaxing, once you get in there. Edge in cautiously because they are HOT.
My favourite volcano is Krakatau, which for USns' information is West of Java, in the Sunda straits between Java and Sumatra. This is the big one that erupted explosively in the 1880s causing multi-coloured sunsets all over the world, a small tidal wave in the English channel. The noise of the eruption was heard as far away as Singapore. To get to Anak Krakatau (child of Krakatoa, the original sank in the great eruption) you go by motor boat from Pantai Carita (the beach of stories). It takes about 3 or 4 hours. There's a little bit of vegetation round the edge of the island but the rest is just a gentle slope of black sand up to the crater. Lots of bits of pumice lying around, but not a lot happening (at least not while I was there -- I hear it's got a bit more active since). The beach of black sand is lovely and the water is very clear. It's a great place to have a swim before the boat takes you back to Carita.
Bingley
Bingley
|
|
|
|
|
Joined: Sep 2001
Posts: 6,296
Carpal Tunnel
|
|
Carpal Tunnel
Joined: Sep 2001
Posts: 6,296 |
Thanks, Stales. That, too, was edifying information. So, mineral water could be called Mineral Mineral, huh?
Before reading what you and others have written here, I would have simply thought of water as a compound, nothing more or less.
Best regards,
MM (That's WW upside-down for Mineral Mineral)
|
|
|
|
|
Joined: Nov 2000
Posts: 866
old hand
|
|
old hand
Joined: Nov 2000
Posts: 866 |
Bingley
Many thanks for your further tales of the fiery furnace within.
There are no active volcanoes in Australia so I have yet to meet my first "live" one. We also have a drive in volcano - but it's as dead as a maggot. On the outskirts of Warrnambool in Victoria. What I would have given for a bit of steam and a sulfurous smell the day I went there!
BTW - you mentioned that Krakatau sank - I was under the impression that the cone was vaporised during the big bang?
I've seen pics of the daughter and she is one pretty place.
stales
|
|
|
|
|
Joined: Mar 2000
Posts: 11,613
Carpal Tunnel
|
|
Carpal Tunnel
Joined: Mar 2000
Posts: 11,613 |
Bingley, what a fascinating tale! Thank you. Volcanoes being rather thin on the ground (hi, CK!) in Kentucky, I am having a hard time envisioning a drive-in one. I am imagining a road lined with booths, with sellers hawking "genuine lava rocks", tin miniature models of the mountain, etc.
|
|
|
|
|
Joined: Apr 2000
Posts: 3,065
Carpal Tunnel
|
|
Carpal Tunnel
Joined: Apr 2000
Posts: 3,065 |
Pictures of Krakatau: http://volcano.und.nodak.edu/vwdocs/volc_images/southeast_asia/indonesia/krakatau.html The accompanying text says collapse of the caldera, so it seems that at least some of it sank. > There are no active volcanoes in Australia so I have yet to meet my first "live" one. We also have a drive in volcano - but it's as dead as a maggot Why a maggot? They're alive surely, even if they don't give off vapours and a sulphuric smell. Bingley
Bingley
|
|
|
|
|
Joined: Apr 2000
Posts: 3,065
Carpal Tunnel
|
|
Carpal Tunnel
Joined: Apr 2000
Posts: 3,065 |
Well, they didn't have tin models, but down one of the paths leading away from the car park they did have wood carvings, seashell mobiles, sweaters, tortoiseshell ornaments, T-shirts, and other souvenirs, and guys with polaroid cameras were wandering round offering to take your picture at the volcano.
Bingley
Bingley
|
|
|
|
|
Joined: Nov 2000
Posts: 866
old hand
|
|
old hand
Joined: Nov 2000
Posts: 866 |
dunno why we say that about maggots - it's illogical (illogic?? to bring in another thread) but in common usage.
Although I mentioned that we don't have active volcanos IN Australia, it is ironic (yet another thread!) that there is such a thing as an active Australian volcano. Furthermore, it's the highest Australian mountain! Only one thing - the volcano in question is Big Ben - and it's on Heard Island, way down in the southern Ocean, well on the way to Antarctica. At 2,745m ASL, Big Ben is 500m higher than the tallest mainland peak of Mt Kosciusko (2,229m ASL).
This is one that pops up at quiz nights - along with "What is the tallest mountain known?" (Answer = Olympus Mons - on Mars)
BTW: When I say "active", that point is debatable in regard to Big Ben. In the texts BB is generally referred to as dormant, but some fumarolic activity and a possible lava flow were noted in March this year.
stales
|
|
|
|
|
Joined: Jul 2000
Posts: 3,467
Carpal Tunnel
|
|
Carpal Tunnel
Joined: Jul 2000
Posts: 3,467 |
stales:
OK. OK. Five years of earth sciences in grade school and high school DOWN the drain! You would think I am old enough to know that never doesn;t mean it!
Another interesting element is gallium, which melts in your hand. I don;t know much about it, but I think it's used for the fusible links in fire sprinklers because it can be alloyed to melt at a very specific temperaure.
Ted
TEd
|
|
|
|
|
Joined: Jan 2001
Posts: 13,858
Carpal Tunnel
|
|
OP
Carpal Tunnel
Joined: Jan 2001
Posts: 13,858 |
Dear TEd: Gallium arsenide used to be important in manufacture of semi-conductors, and probably still is, though things change fast in that business. I can't remember what properties made it so useful.
|
|
|
|
|
Joined: Jan 2001
Posts: 1,156
old hand
|
|
old hand
Joined: Jan 2001
Posts: 1,156 |
Gallium arsenide used to be important in manufacture of semi-conductors, and probably still is, though things change fast in that business. I can't remember what properties made it so useful.Methinks it's the number of valence electrons. Too lazy to look it up; I should be working!
|
|
|
|
|
Joined: Nov 2000
Posts: 866
old hand
|
|
old hand
Joined: Nov 2000
Posts: 866 |
I remember seeing an episode of Candid Camera where the teaspoons in a diner were made of gallium.
Patrons would nonchalantly stir their cuppa, only to pull out a spoonless handle - the rest having melted in the coffee!!
Hopefully the camera crew got to each punter before they swallowed any!
stales
|
|
|
|
|
Joined: Mar 2000
Posts: 11,613
Carpal Tunnel
|
|
Carpal Tunnel
Joined: Mar 2000
Posts: 11,613 |
Patrons would nonchalantly stir their cuppa, only to pull out a spoonless handle Ohmigawd, how funny!
|
|
|
|
|
Joined: Jan 2001
Posts: 13,858
Carpal Tunnel
|
|
OP
Carpal Tunnel
Joined: Jan 2001
Posts: 13,858 |
That could give the restaurant's coffee a bad reputation.
|
|
|
|
|
Joined: Nov 2000
Posts: 866
old hand
|
|
old hand
Joined: Nov 2000
Posts: 866 |
> That could give the restaurant's coffee a bad reputation
You don't need to use gallium to get the same effect with airline coffee. Their stuff has the same effect on stainless steel!
stales
|
|
|
|
|
Joined: Sep 2001
Posts: 6,296
Carpal Tunnel
|
|
Carpal Tunnel
Joined: Sep 2001
Posts: 6,296 |
Something dead is feasted on by maggots. The term makes sense, figuratively applied.
Gallium: Any others like it? And what's gallium's SG? Maybe Dali's watches were made of it...?
|
|
|
|
|
Joined: Jan 2001
Posts: 13,858
Carpal Tunnel
|
|
OP
Carpal Tunnel
Joined: Jan 2001
Posts: 13,858 |
I looked at dictionary for etymology of maggot, and was surprised to find it related to word "mawkish".
|
|
|
|
|
Joined: Apr 2000
Posts: 3,065
Carpal Tunnel
|
|
Carpal Tunnel
Joined: Apr 2000
Posts: 3,065 |
Wordwind, weren't maggots pieces of music at one time? Sort of light pieces a busy Renaissance man would jot down in his spare time?
Bingley
Bingley
|
|
|
|
|
Joined: Sep 2001
Posts: 6,296
Carpal Tunnel
|
|
Carpal Tunnel
Joined: Sep 2001
Posts: 6,296 |
Bingley, I'm still searching for music and maggots--you would know that there would be a rock group, huh? But look at the link below, and scroll down to 1100 - 1700 AD for something on spotaneous regeneration... Will try to refine my search a bit and see whether there's any musical maggots. (Remember Maggot in The Dirty Dozen?) http://www.mygradnet.com/Biotech/early_history.htmAnd skating on ice: Wouldn't ice be of the lightest minerals? It's certainly found in the natural world, and it floats on water... What would be the metaphorical situations here for when our coldest natures float upon our liquid ones? Brrrrrr regards, Figure Eight
|
|
|
|
|
Joined: Aug 2001
Posts: 2,605
Carpal Tunnel
|
|
Carpal Tunnel
Joined: Aug 2001
Posts: 2,605 |
http://www.biology.clc.uc.edu/courses/bio114/spontgen.htm: It is easy in hindsight to regard earlier views with smug superiority, for the notion of "spontaneous generation" is of course ridiculous on the scale of complex organisms. However, past generations aceepted "spontaneous generation" only as applicatble to certain lower animal, for which that belief was supported by good evidence and was well accepted by reputable authority, in particular by Aristotle. http://www.accessexcellence.org/AB/BC/Spontaneous_Generation.html: It was not until quite late that careful experimentation demonstrated that not even bacterial life arises by spontaneous generation. Louis Pasteur devised the clinching experiment in 1859.
|
|
|
|
|
Joined: Jan 2001
Posts: 13,858
Carpal Tunnel
|
|
OP
Carpal Tunnel
Joined: Jan 2001
Posts: 13,858 |
Dear WW: After managing to avoid a large number of rock groups I found one reference as an example of your word "maggot". No definition, however.
A Maggot
Thomas Arne (1710-1778)
The large and appreciative audience were particularly enchanted with the
delightful Maggot by Arne,
|
|
|
|
|
Joined: Sep 2001
Posts: 6,296
Carpal Tunnel
|
|
Carpal Tunnel
Joined: Sep 2001
Posts: 6,296 |
Note on Arne: ARNE (m) Short form of ARNOLD and Scandinavian names beginning with the Old Norse element arn meaning "eagle".
...I've lost the site. Sorry I can't post the url, but will go back and find it.
Thomas Arne is the only one I can find, too, who composed maggots. Now to compose a maggot, be very patient with it. Give it lots of reassurance, encouragement, and advise it to take deep breaths. Deep breathing is essential here if a maggot is to be composed.
Scoring maggots (now that's another thing altogether),
DubDub
PS: Back to minerals: I asked above would ice be of the lightest minerals? SG and all that jazz?
|
|
|
|
|
Joined: Mar 2001
Posts: 4,189
Carpal Tunnel
|
|
Carpal Tunnel
Joined: Mar 2001
Posts: 4,189 |
And why is is that military drill instructors are so fond of calling their new recruits, "Maggots!"?
|
|
|
|
|
Joined: Jan 2001
Posts: 13,858
Carpal Tunnel
|
|
OP
Carpal Tunnel
Joined: Jan 2001
Posts: 13,858 |
I would like to have a dollar for every ti;me I have seen "erne" in a crossword puzzle.
|
|
|
|
|
Joined: Mar 2000
Posts: 11,613
Carpal Tunnel
|
|
Carpal Tunnel
Joined: Mar 2000
Posts: 11,613 |
What would be the metaphorical situations here for when our coldest natures float upon our liquid ones?
Wordwind, I have thought and thought about this intriguing question, and have been unable to come up with anything other than the hackneyed he/she acts cold, but that hides a warm heart. Could you provide any examples or pointers?
|
|
|
|
|
Joined: Sep 2001
Posts: 6,296
Carpal Tunnel
|
|
Carpal Tunnel
Joined: Sep 2001
Posts: 6,296 |
Jackie... I threw the ice upon water out as bait. I've packed it away in my head to see when something will remind me of it. I don't know how other people think, but I see our inner workings as being fluid. Some are fluid in and out; then there are those who are fluid in, but ice without, like a frozen pond.
Speaking of: What was it that Emerson said about (and here comes a horrible paraphrase) the majority of people spend their lives skating on surfaces?
Back to ice: Then there are those who come out of the night like icebergs, they are so deadly and rigid. But that's really an insult to ice bergs. (Is it one word or two?)
And, to maintain my persistence, is ice actually the lightest of minerals SG-wise?
I've gone fond of thinking of myself, incidentally, as being dense as iridium this week. Thanks, Stales!
Dub
|
|
|
|
|
Joined: Jan 2001
Posts: 13,858
Carpal Tunnel
|
|
OP
Carpal Tunnel
Joined: Jan 2001
Posts: 13,858 |
Dear WW: could you by any chance be thinking of Emerson's friend?
The mass of men lead lives of quiet desperation.
- Henry David Thoreau
As a bit of sad trivia, I read recently that both Emerson and Thoreau were victims of tuberculosis.
|
|
|
|
|
Joined: Sep 2001
Posts: 6,296
Carpal Tunnel
|
|
Carpal Tunnel
Joined: Sep 2001
Posts: 6,296 |
wwh: The lives of quiet desperation I'm familiar with as Thoreau's. I don't know whether Thoreau also wrote the comment about the majority of people spending their lives skating on surfaces. He certainly could have.
About Emerson, I remember having heard that he climbed (spelling error alert) Qtaden in a suit.
Dub
|
|
|
|
|
Joined: Nov 2000
Posts: 866
old hand
|
|
old hand
Joined: Nov 2000
Posts: 866 |
WW
Sorry I didn't rsvp IMMEDIATELY, but I spent the last couple of days earning my keep, to-ing and fro-ing from a mine site near Mt Magnet, about 600km N of Perth (in the middle of nowhere).
Interesting q about the SG of ice. You are quite correct that, because it floats on water, it is less dense / has a lower SG than water. What that value is I don't know - haven't had time to look it up.
Why is it so?
When water is frozen it expands - or, in scientific terms, its volume increases. Thus, a volume of ice (say one cc) will, when thawed, produce less than one cc of water. SG is calculated as the mass (or "weight" - to use the incorrect vernacular) of a substance per standard unit of volume (one cc). Thus it's easy to see that a cc of ice has less mass than the same volume of water, a lower SG and that it will float. well I think I can follow all that!!
A WILD stab as to what ice's SG is.....considering that seven eighths of an iceberg sinks in sea water (which is denser than pure water), it is tempting to assume that the SG of ice is around 12.5% less than that of water - ie 0.875. Evenkite, the candidate for lowest SG last week, has an SG of 0.87 so it would be a close call if these wild assumptions are anywhere near correct. If I knew what the coefficient of expansion (ie the volume change) for the freezing of water was we'd have the answer!
stales
|
|
|
|
|
Joined: Jan 2001
Posts: 13,858
Carpal Tunnel
|
|
OP
Carpal Tunnel
Joined: Jan 2001
Posts: 13,858 |
Dear WW: I could not find reference to Emerson climbing Katahdin in a tuxedo. But he might have. He could not have found a sporting good store.
|
|
|
|
|
Joined: Nov 2000
Posts: 866
old hand
|
|
old hand
Joined: Nov 2000
Posts: 866 |
Jackie - I apologise if somebody answered your q elsewhere in this thread - had a quick look but couldn't find one...
I think the word that was buzzing around your head may have been "scoria" - it's easy to see why "scree" may have popped out instead.
Scoria is a generic term for all the bits of sh** that are chucked out by a volcano - and in particular (pun intended), the smaller stuff. Pumice and volcanic "ash" are examples of scoria.
stales
|
|
|
|
|
Joined: Sep 2001
Posts: 6,296
Carpal Tunnel
|
|
Carpal Tunnel
Joined: Sep 2001
Posts: 6,296 |
Stales, If you come across the SG of ice, great. I'd be interested in reading here how ice compares to Evenkite.
In the spirit of rock solid scientific investigation,
WW
|
|
|
|
|
Joined: Sep 2001
Posts: 6,296
Carpal Tunnel
|
|
Carpal Tunnel
Joined: Sep 2001
Posts: 6,296 |
Dear wwh: Thanks for Katahdin, not Qtadin!! I'm not qihddin'!
DubDub
|
|
|
|
|
Joined: Jan 2001
Posts: 13,858
Carpal Tunnel
|
|
OP
Carpal Tunnel
Joined: Jan 2001
Posts: 13,858 |
Dear WW: I was a boy long enough ago that my parents could let me stay out until 3AM on moonlit nights during Christmas holidays. There was a twenty acre pond that had been created by damming a large brook to cut ice for sale long before refrigerators were invented. There was a large island on which we were allowed to build huge bonfires. I still remember the sounds the ice made, expanding until suddenly huge cracks would form to releave the stress. The specific gravity of ice would be depend on the temperature of both the ice and the water, and so would not be useful. Let it go that it is less than one.
Think of what the world would be like if ice sank. The oceans would be solid except for a film on the surface in summer. Life as we know it might be impossible.
|
|
|
|
|
Joined: Aug 2001
Posts: 2,605
Carpal Tunnel
|
|
Carpal Tunnel
Joined: Aug 2001
Posts: 2,605 |
Crossthreading wildly: from Jackie's lovely subject-line, "Fire and Ice", to a brief poem of that title by Robert Frost: http://www.bartleby.com/155/2.html
|
|
|
|
|
Joined: Jan 2001
Posts: 13,858
Carpal Tunnel
|
|
OP
Carpal Tunnel
Joined: Jan 2001
Posts: 13,858 |
And the contraction Keiva mentioned of water just before it freezes is what slowly destroys mountains,and makes potholes in roads, by water getting into any crack and then expanding with great power, though for a short distance. Many primitive people quarried stone by laboriously drilling a line of holes, filling them with water, which when it froze would split off a large block.
|
|
|
|
|
Joined: Jul 2000
Posts: 3,467
Carpal Tunnel
|
|
Carpal Tunnel
Joined: Jul 2000
Posts: 3,467 |
Bill:
Perhaps even more interesting is another characteristic of water. Most things, as they get colder, become smaller in size though of course retaining the same mass. A red-hot iron ring will contract around a wooden wheel to become so tight the spokes creak in protest.
Water is like this down to 4 degrees Centigrade. It's at that point that water is its densest. But as you cool the water further towards zero Centigrade, it actually expands in size! I cannot remember the chemistry/physics reason why this is so, but 'tis true. In fact, the gram was at one time defined as a cubic centimeter of water at the temperature of 4 Centigrade because that way everyone can determine exactly what a gram is.
Or should I have been saying Celcius?
TEd
TEd
|
|
|
|
|
Joined: Nov 2000
Posts: 866
old hand
|
|
old hand
Joined: Nov 2000
Posts: 866 |
dubdub
Found out all about ice.
The reference states that ice is one of the most common minerals on the planet. Interestingly however, it adds that there are no minerals with similar properties - it is unique.
Pure ice has an SG of 0.917 (well, I was close), a hardness of 1.5 (ie it will scratch talc), a vitreous lustre, no cleavage and its tenacity is rated as "brittle".
I'm now off to research SG's. As ice technically doesn't exist at standard temperatures and pressures, I'm wondering if STP is part of the definition after all.
google-eyed stales
|
|
|
|
|
Joined: Nov 2000
Posts: 866
old hand
|
|
old hand
Joined: Nov 2000
Posts: 866 |
The term specific gravity, symbolized sp gr, (what about SG?) refers to the ratio of the density of a solid or liquid to the density of water at 4 degrees Celsius. The term can also refer to the ratio of the density of a gas to the density of dry air at standard temperature and pressure, although this specification is less often used. Specific gravity is a dimensionless quantity; that is, it is not expressed in units.
I'm assuming that "at 4 degrees Celsius" refers only to the water in the equation???? Thus, one would calculate the density of ice at whatever temperature and pressure and then ratio it against the value for water to get the sp gr.
stales
|
|
|
|
|
Joined: Sep 2001
Posts: 6,296
Carpal Tunnel
|
|
Carpal Tunnel
Joined: Sep 2001
Posts: 6,296 |
Thanks, Stales, for the research. I'm going to send this thread to a local geologist and see what his take is on it. Will post his response later in the week.
Best regards,
Dub
PS: that 4 degrees Celsius seems a bit unfair to ice. By the way, I really enjoyed your quick calculation a few posts back about your estimated SG of ice. Impressive!
|
|
|
|
|
Joined: Jan 2001
Posts: 1,156
old hand
|
|
old hand
Joined: Jan 2001
Posts: 1,156 |
I'd just like to add to this list, be careful about icebergs. They also contain salt. I know you all think that the salt should be excluded as the water freezes, but apparently it is not totally left behind. And other things can happen:
"The density of pure water at 0°C is 999.9 kg/m^3 and that of pure ice is 916.8 kg/m^3 [that would be an SG of 0.9168]. However the density of sea-ice may be greater than this last figure (if brine is trapped among the ice crystals) or less (if the brine has escaped and gas bubbles are present.) Values from 924 to 857 kg/m^2 [in terms of SG, 0.924 to 0.857]were recorded on the Norwegian [yay Norway] Maud Expedition"
From Descriptive Physical Oceanography by Pickard and Emery, 1990.
|
|
|
|
Forums16
Topics13,913
Posts229,317
Members9,182
| |
Most Online3,341
Dec 9th, 2011
|
|
|
0 members (),
628
guests, and
1
robot. |
|
Key:
Admin,
Global Mod,
Mod
|
|
|
|
