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23
votes
2answers
2k views

Are there pockets of liquid carbon dioxide in Earth's oceans?

The carbon dioxide phase diagram shows that at high pressure and normal temperature CO2 becomes liquid. Since it is heavier than water, I wonder if there are lakes of liquid CO2 at the bottom of the ...
23
votes
1answer
2k views

What causes 'positive' lightning to be rarer, higher charged, and longer lasting than 'negative' lightning?

Why is 'positive' lightning rarer, brighter, higher charged, and longer lasting than 'negative' lightning? Are there any other unique characteristics to positive lightning that sets it apart from ...
23
votes
0answers
348 views

How reliable were early measurements of palaeomagnetic directions?

The methodology and equipment for palaeomagnetic studies in the 1960s and 1970s was often rather primitive by today's standards. For example, Doell and Cox (1967) imply that the standard procedure for ...
22
votes
3answers
22k views

Where can obsidian be found?

Where is obsidian found? Is it typically found on the surface or underground? If underground, how far under (meters or feet would be perfect)? Also, is it found everywhere on Earth, or just in areas ...
22
votes
6answers
120k views

Is there a difference between rock and stone?

I couldn't find the definitions from either source: Geology Dictionary Glossary of Geologic Terms
22
votes
1answer
13k views

Why were both the sun and the moon red today?

Today was a normal day, except the sun and moon colors were strange. After 5pm, the sky was covered with cirrostratus-like translucent clouds and the sky was a blend of blue and grey. Everything ...
22
votes
3answers
9k views

How to distinguish P, S, Love, and Rayleigh waves in a seismogram?

What features should I look for to determine each of these kinds of waves in a seismogram? What signal processing methods (filters, transforms, etc...) should I use to determine them?
22
votes
2answers
8k views

“Five of the Solomon Islands disappeared” due to sea level rise, how is this possible so quickly?

The text of the introduction to the BBC Podcast Sea Levels Rise; The Compass, Living on the Edge Episode 1 of 4 says: Five of the Solomon Islands have disappeared, many more are becoming ...
22
votes
3answers
630 views

Is there any explanation for the large amount of sea ice around Antarctica in 2014?

As can be seen from the below data, for the past year or so (2014), sea ice surrounding Antarctica has been well above normal. Currently, Antarctic sea ice is at an all-time record high for this time ...
22
votes
4answers
4k views

What causes bottom water to rise?

The water close to the deep ocean floor is called bottom water. It may be located in deep valleys or trenches. I understand that water flowing to the Arctic will sink there, because it's saltier and ...
22
votes
1answer
2k views

How can the world's sea level rise and fall simultaneously?

I have just been reading this article on Gizmodo (known for its hard science I know), that talks about sea level rising by up to 3 feet(!). In the article and video, created from information from ...
22
votes
2answers
422 views

What are some of the strongest theories against the existence of mantle plumes?

Among the people I interact with in the geodynamics community, it seems that almost all of us are in full support of the mantle plume theory. What are the strongest arguments against this theory? Is ...
22
votes
1answer
558 views

How is ocean salinity measured from space?

Since 2009, two satellites (SMOS from ESA and Aquarius from NASA) are providing global salinity measurements. While ocean temperature is easily derived from infrared radiation for instance, what ...
22
votes
2answers
362 views

What properties must a rocky body possess in order to exhibit plate tectonics?

The Earth exhibits plate tectonics, but the other terrestrial planets do not (though Mars and Venus may have exhibited plate tectonics in the past). What is "special" about Earth that allows it to ...
22
votes
1answer
594 views

Why are most peninsulas oriented north-south?

Weird question, bear with me. Most large peninsula on Earth are oriented southwards (and most of the rest northwards), much fewer east or west. Some examples: Florida, Californa peninsula, Yucatan, ...
22
votes
2answers
841 views

How can the average coldest day of the year be before the winter solstice?

There are parts of the U.S. where, on average, the coldest day of the year comes before December 21st. [source] How can this be? Why would temperatures start rising again even while days are still ...
22
votes
1answer
313 views

Estimating the permeability tensor of an oil field by remote sensing

I work a lot with numerical methods to solve multiphase flow in porous media for oil applications. In our field, we often use Darcy's law which states that the flux is negatively proportional to the ...
22
votes
1answer
137 views

Placement of crustal thickness estimation from 1D inversion of surface wave dispersion curves

Seismic surface waves present a characteristic dispersion behavior in which different frequencies travel at different speeds. This characteristic dispersion curve depends on the shear and ...
22
votes
2answers
2k views

Peak phosphorus - what are the sinks?

The minable phosphorus reserves are limited. Where is the mined phosphoprus landing, what are the global phosphorus sinks? I would assume that most phosphorus is used for fertilizer and ultimately ...
21
votes
7answers
2k views

What tools allow a quick comparison of NetCDF output from ocean models?

I am writing my own MATLAB scripts to do most of the visualization and data analysis of model results. I wonder if there is a quicker way for visual comparison of simulation results gained from ...
21
votes
5answers
4k views

Is there a database of global rainfall time series?

Is there any institute out there collecting time series data of precipitation, and making them accessible online? I need data for a few different locations, but: Low spatial resolution is fine. For ...
21
votes
2answers
6k views

Does Earth's air leak into space over time?

From my current understanding, Earth's atmosphere and air are held by the balance of two forces: 1. Earth's gravity and 2. Air pressure from air out to space. Is my understanding correct? So, do ...
21
votes
3answers
7k views

What percent of the Earth's core is uranium?

What percent of the Earth's core is uranium? And how much of the heat at the core is from radioactive decay rather than other forces?
21
votes
2answers
2k views

In what geological situations can I find gold?

I've heard that gold ore is often associated with quartz veins. What geological processes enable gold particles to naturally cluster together like this? What characteristics/properties should I look ...
21
votes
3answers
415 views

Is fracking likely to produce earthquakes?

Post Christchurch-2011 earthquake, there was much concern that fracking in the surrounding areas might lead to further quakes, as was rumoured to have happened elsewhere in the world. Is there ...
21
votes
2answers
1k views

What caused the Younger Dryas cold event?

During the termination of the latest ice age the warming climate leading from glacial to interglacial conditions was abruptly reverted by a distinct but short (about 1300 years in duration) cold event,...
21
votes
2answers
326 views

How can I improve the numerical stability of a coastal hydrodynamic model?

I am working with a coastal hydrodynamic model in the MIKE3 modelling package. MIKE3 uses the finite volume method to solve the shallow water equations with explicit timestepping, over a triangular ...
21
votes
1answer
530 views

Is there geological evidence that the moon once collided with the Earth?

I've seen models in astronomy that show how the Earth-Moon system must have come together after a collision. However, I have not heard whether there is any actual physical evidence on Earth that ...
21
votes
1answer
2k views

Why do Earth and Venus have different atmospheres?

Venus appears to be the closest to Earth in mass, density, size, etc. - though they clearly have different atmospheres. Why do Earth and Venus have different atmospheres?
21
votes
2answers
7k views

Plate Tectonics: Is it possible to have an ocean-continent divergent boundary

I am procedurally generating planets for an open world space sandbox game. I am using a rough simulation of tectonic plates to create mountain ranges and other geological features. A planet surface ...
21
votes
2answers
2k views

Why does phosphate rock contain uranium?

I have been doing some research on the issue of phosphogypsum pollution. Phosphogypsum is a waste by-product formed with the "wet process" method of extraction of phosphoric acid out of ...
21
votes
2answers
5k views

Is there an upper bound to the amount of rain that can fall in an hour?

The record for most rainfall in a single hour is 12 inches (30.5 cm), set in Holt, Missouri, in 1947. What is the maximum amount of rainfall that could theoretically occur in an hour?
21
votes
2answers
3k views

How do tropopause folds form and do they have any impact on synoptic scale weather?

What is the process that creates a tropopause fold? Do these features have any significant impact(s) on weather patterns or the atmosphere?
21
votes
1answer
726 views

Significant difference between averaged wind speeds and averaged wind power density, for wind generation modelling?

Climate models outputs, particularly the reanalysis datasets, output wind speeds as zonal and meridional averages for the modelled time period (typically 1, 3 or 6 hours). So we get a 2-dimensional ...
20
votes
6answers
19k views

Why doesn't the sun reach its highest point overhead at exactly 12:00 noon?

Many sources state that 12:00 noon is the high-point or mid-point of the sun's path across the sky. However, for where I am, this is obviously wrong. In my own town the high point of the sun occurs ...
20
votes
4answers
9k views

What is the deepest we have ever gone into the Earth?

I remember Journey to the Center of Earth and wonder: What is the deepest in the Earth surface or below sea level we have traveled either by foot, sub, drill or camera?
20
votes
5answers
1k views

Academic but accessible defense of the scientific understanding of anthropogenic climate change?

I'm an intelligent and well-educated guy, but all of my schooling has been in economics, statistics, and public policy. I'm interested in reading a thorough explanation/defense of the scientific ...
20
votes
3answers
5k views

Why don't scientists use fire entry suits to study volcanoes?

It seems like the only personal protective equipment (PPE) that volcanologists use are aluminized suits that don't provide any protection from direct contact with lava, making an unexpected splash ...
20
votes
2answers
4k views

What are the major differences between weather models and climate models?

Some weather models include GFS (Global Forecast System) and NAM (North American Mesoscale Model). Some climate models include CCSM (Community Climate System Model) and the NASA GISS (Goddard ...
20
votes
3answers
1k views

Why does Volcano Lightning occur?

There are many pictures I've seen of lightning coming out of the plume of smoke caused by a volcano (Often called 'Volcano Lightning'). Example: Why does this happen?
20
votes
3answers
5k views

Why is March colder than September in Northern Hemisphere?

Forgive my ignorance of the subject but I was always wondered about the exact reason of this phenomenon. Vernal equinox happens around March 20, whereas autumnal equinox happens around September 22, ...
20
votes
4answers
12k views

Will the Earth ever stop rotating?

It is well known that the Earth's rotation is slowing down and that millions of years ago there was a point in time where there was only a mere 20 hours in a day on Earth. My question is in two parts....
20
votes
3answers
2k views

Can the overuse of geothermal energy become an environmental concern? [duplicate]

At what power output would we be using so much geothermal energy that we cool the core enough to endanger the Earth's magnetic field and have to stop using it? Is this a conceivable concern for a ...
20
votes
3answers
1k views

What are rare earths and why do they cluster near alkaline magmatism?

'Rare earths' play a vital role in the modern economy, and they are becoming more of a point of focus in geopolitical realms. What are 'rare earths' and why do they appear to cluster in association ...
20
votes
2answers
6k views

What is the origin of the ocean's salt?

We know we cannot live without salt, but an investigation into the origins of ocean's salt leads one to believe that this issue is not fully resolved yet. What geological phenomenon caused the earth ...
20
votes
1answer
67k views

Why are oceanic plates denser than continental plates?

In the theory of tectonic plates, at a convergent boundary between a continental plate and an oceanic plate, the denser plate usually subducts underneath the less dense plate. It is well known that ...
20
votes
4answers
2k views

What is the 'natural variation' in global temperature that climate-change skeptics mention?

I was wondering if there really was some natural variation that keeps getting cited by climate-change skeptics that predicts a warming? The only such variation I can think of would be the milankovitch ...
20
votes
4answers
2k views

What would a replacement for SEGY look like?

I have been having a miserable time this week reading SEGY files. This is data from the largest seismic acquisition company in the world whose client is the 7th largest oil company in the world. So if ...
20
votes
1answer
330 views

Why Earth's magnetic poles are (and were) in their positions?

This is a sort of a follow-up question to What causes the Earth to have magnetic poles? The Earth has magnetic fields, and according to dynamo theory I roughly understand why. If the Earth's rotation ...
20
votes
2answers
978 views

How are the banded-iron-formation iron-ores formed?

Many of the richest and purest iron ores are found in so called banded iron formations, cm thick magnetite or hematite layers intermixed with iron poor rock layers. Since these are usually of pre-...

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