# All Questions

4,341 questions
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### ROCK ID: Heavy, reddish/orange with black, smooth layer from Oklahoma, USA

ROCK ID: Heavy, reddish/orange with black, smooth layer from Oklahoma, USA
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### Aren't fresh water deposits renewed by water cycle?

I have recently watched "How Many People Can Live on Planet Earth?" documentary with David Attenborough. In it, among one of the main factors that will limit total human population Earth can support ...
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### Is there really a “last chance” to stop climate change given current policies out of China?

I was reading this article: https://www.cnn.com/2018/12/10/world/climate-change-us-coal-cop24/index.html Which basically says that the US is destroying our last chance at making real changes to stop ...
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### Ages of the Andean Cordilleras

What is the timing of the rise of the Andes, especially if focused on the chronosequence differences among (Western, Central, Eastern) Cordilleras uplift.
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### Identification of these metal rocks

Very heavy rocks. If you look close you see crystals inside. Not very reactive to hydrochloric acid. Not magnetic. Found together on the side of the road, at Chiltern, north east Victoria, Australia,...
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### Are there natural-forcings climate projections over the 21st century?

CMIP5 offers natural-forcings-only simulations over 1850-2005, which allows comparison with the historical simulations, which allows us to show how anthropogenic forcings have affected the climate ...
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### Can someone please identify this rock

gray stones with short small dark shiny lines all over it found on beaches of Newport Rhode Island
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### Why is the Lithosphere-Asthenosphere Boundary an Isotherm

My understanding of the LAB is that it represents the point in the earth where the mantle undergoes a temperature activated mechanical change. The temperature of the boundary depends on the melting ...
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### What has formed this rock and its colours? [on hold]

I found this rock in Oregon as a boulder in the countryside. It almost looks like a cut of meat in pattern with white crystal look and pops of lavender it weighs about 25 lbs
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### largest earthquake not in a subduction zone

Whats the largest earthquake since 1900 that was not in a subduction zone (not a megathrust). Wikipedia says that Since 1900, all earthquakes of magnitude 9.0 or greater have been megathrust ...
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### Can someone identify these dark red rocks?

It has pretty even color - dark red rock with white snowflakes all over it. I found it in MA, near lake, where water seems to wash out the shore. The main block was too big to take (but I saw it), so ...
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### How many kg $ha^-$$^1 of exchangeable Mg^2$$^+$ is there in the top 15cm of this field?

Soil testing from a well-drained soil sample in 0-15cm depth of a farmers field provides the following information: • Wet weight of a soil sample from a volume of 100 $cm^3$: 200 g • Moisture ...
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### Is this Obsidian?

This was found by a family member in Australia. Can anyone identify from the photo? I'm thinking Obsidian
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### why igneous phosphate rocks contain less uranium than sedimentary rocks?

Sedimentary rock phosphates contain much higher concentrations of potentially hazardous elements (As, Cd, Cr,Pb, Se and U)than igneous rock phosphates. Why? Is it because U concentration in magmatic ...
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### How is heavy rainfall determined in National Climate Assessment

I'm trying to understand/reproduce/revise this chart in the Southeast section of the United States National Climate Assessment. The truncated scale for the bars is what caught by eye as a classic ...
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### Could the HIawatha meteroite cause a big flood?

A big iron meteorite hit Greenland, possibly hitting the ice cap https://en.wikipedia.org/wiki/Hiawatha_Glacier What would be the effects, and would there be big flooding ?
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### What is the cause of temporary smell and black color of underground water?

We have a well (about 1200KM away from sea and 60 meter deep), the water when taken out has slightly dark color and has smell. But strangely in about 12 hours the smell and black color vanishes and ...
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### How do I get a value for jade stone [on hold]

cascading jade stone 50lb piece glows when bright light on it where do I go to get grade value and possibly sale this in Washington state
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### Before the artificial changes of the Aral Sea, what was its average depth and salinity?

The Aral Sea was a major lake of the USSR until it suffered artificial changes, which began sometime no later than the 1960s. I am unfortunately not sure when major artificial changes began. ...
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### What is this rock and how was it formed? [on hold]

Please help identify the rock and what causes the light brownish 'nodules'
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### Need help identifying rock formation

so this is my first time here because I need help in identifying the features on this rock formation. https://www.flickr.com/gp/158064920@N05/6USrY9 Thank you in advance.
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### Which of these is NOT made from fossil fuels? [on hold]

Of metal and coal which is NOT made from fossil fuels. Coal IS fossil fuels, while metal is naturally formed.
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### Lightning moving close to the ground in Magalia, CA last July, months before the Camp Fire

I made a fire defense space about 100' by 50' behind my two level home on a 20% slope surrounded by old, tall pines. On July 14, 2018, I saw thin white jagged lines moving across the open space that ...
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### Petrified wood or something else?

I found this while digging through piles of river runoff dirt/rocks that were removed after flooding from farm land. It was originally located in Central Iowa, Story County, USA. I am new to this but ...
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### What two mineral/stones are these that formed together?

NEW EDIT. I took a sharp knife and scratched at the orange/amber area. The area the blade tip went across would develope a faint white mark; however if I licked my finger and wiped the mark it ...
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### water (or hydrological) year around the world, does it change?

Following the commonly-known USGS definition of Water Year (or Hydrological Year) we know that it starts on the 1st October and ends on the next 30th September. Is this definition valid only for ...
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### Quality control in Seismic Acquisition - How much data is required?

When it comes to land or marine acquisition (oil exploration, for instance), I can see from literature that quality control (QC) is performed during the survey to ensure that the seismic traces ...
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### What is this figurine made of:

Have several of these animal figurines, MADE IN USSR on bottom. Can't figure out what type of rock it is made from. Any ideas?
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### What clays from XRD analysis should be taken into account in Vshale calibration?

I'm working with Well Logs and I want to calibrate my Vshale model with the clays from an XRD analysis that I have from the lab. There are muscovite and biotite, chlorite (secondary), detrital clay ...
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### Could one say that granites are metamorphic rocks, or not at all?

In my old textbooks, granites used to be part of the metamorphic rocks. Is this still true or not ? If not fully true, to which extent ? Could someone point me towards clear examples or definitions ...
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### where to download NASA-NEX daily downscaled datasets?

I'm looking to download a small geographic area of the CMIP5 models part of NASA-NEX dataset. Previously I relied on the Planet OS OpenNEX GDDP website which had a great tool for selecting geographic ...
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### When will the weight of melted polar ice release the (currently stuck) subduction of the oceanic plate West of the Oregon coast?

Melted polar ice water makes the oceans deeper on average. The extra water on top of the oceanic plates makes them sink relative to the continental plates. This relative vertical displacement will ...
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### Why are there no deep caves in the continental US?

According to http://www.caverbob.com/wdeep.htm and http://www.caverbob.com/usadeep.htm, the only cave over 1000m deep in the US is a lava cave in Hawaii. In the continental US the deepest is 505m. On ...
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### Identify tiny green crystals on a pinkish/yellowish rock coming from Epupa Falls on Kunene River North of Namibia

That my first post : I'll try to follow the guidelines. 1) I provide 2 pictures of my sample : the first one from the tiny green crystals themselves, and the second one from the rock supporting the ...
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### Velocity gradient of surface ocean current in dephts

How much speed of surface currents decrease in ocean depth? Approximately? I am wondering if there is any significant gradient within the top 30m ocean layer? Can this be theoretically calculated?
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### How to build a daily streamflow model from past precipitation data?

Background: I am taking a class in which I am the only student. Last class, I was called to go to the blackboard to build a conceptual daily streamflow model from historical precipitation data. I ...
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### Can you identify this rock, please? [closed]

I found this rock at the edge of a field near a fill dirt pile in San Diego, CA
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### What is the relationship between net primary productivity and emergy?

Looking at the Earth system as a whole and considering ecological economics, net primary productivity and emergy are two concepts that strike me as fundamental and likely related. I'm not sure what ...
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### Black and amber stone.

I have a bracelet with an unusual piece of polished stone, black with orange fossil-like inclusions. It would be great if someone could help me identify what this is. Many thanks! The back of the ...
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### Deep hole create inside the earth [closed]

I see some videos, in which big hole create in earth. It is most deep hole in which nothing see inside. My question is this, how this hole create? And why this hole in circle shape?
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### Could dust blown up by a comet impact render the air unbreathable?

In the docudrama Super Comet After the Impact, the impact is shown to have made the air within a few miles of it unbreathable, and humans need gas masks to breath in this area. How realistic is this? ...
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### Can someone please help me identify what this is… stromatolite…coral…or neither…help [closed]

Hi I'm trying find out what kind of rock this is.... I have a chunk the size of akeg of beer looks like muddy coral on the bottom and coral like inside and agatized sponge or coral or something else ...
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### Rock type identification

Found this rock in western Ireland among many other like this one, its scratch resistant to a stainless steel blade, its blackish with light green spots and some tiny Pyrite crystal inclusions, it ...
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### What is are the benefits of map 500 hPa geopotential for weather forecasting?

From the weather forecasting perspective: what is the main reason for showing just map of 500 hPa geopotential? Are there any practical or theoretical reasons? Why do not show 600 hPa geopotential or ...
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### Are plastics a carbon sink and how much carbon is released to the atmosphere making them?

If we were to make some technical jump to renewable fuel and renewable energy, would making plastics from oil release green house gasses, how much, and would plastic function as a carbon sink? Sorry ...
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### Why does CO2 cause heating in troposphere but cooling mesosphere?

Why does CO2 cause heating in troposphere but cooling mesosphere? Can anyone explain this?
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### Formation of Hematite on Mars via Perchlorates as an Oxidizer

Hematite on Mars is generally thought to have formed either in pools of water or from volcanic activity. A comment to the answer to the question: How do hematite and magnetite form? states that ...
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### Shouldn't height of tropopause and troposphere be different?

I have seen that height of troposphere is given as 8 to 16 km on various sites, but doesn't it also include the thickness of tropopause layer ? Tropopause is a layer with certain thickness where ...