Geology

Volcanic hazards aren't limited to eruptions, debris landslides can also cause a great deal of damage and loss of life. 

Stratovolcanoes, with their steep, conical shapes made up of lava and unconsolidated mixed materials, can reach a critical point of instability when they overgrow their flanks. This leads to partial collapse, and the product of this slope failure is a large-scale, rapid mass movement known as a catastrophic landslide or debris avalanche. 


The moon's surface has by millions of craters but it also has over 200 holes – and those steep-walled pits that in some cases might lead to caves that future astronauts could explore and use for shelter, according to new observations from NASA's Lunar Reconnaissance Orbiter (LRO) spacecraft.

The pits range in size from about 5 yards across to around 1,000 in diameter, and three of them were first identified using images from the Japanese Kaguya spacecraft. Hundreds more were found using a new computer algorithm that automatically scanned thousands of high-resolution images of the lunar surface from LRO's Narrow Angle Camera (NAC).


By measuring how fast Earth conducts electricity and seismic waves, researchers have created a detailed picture of Mount Rainier's deep volcanic plumbing and partly molten rock that will erupt again someday.

In an odd twist, the image appears to show that at least part of Mount Rainier's partly molten magma reservoir is located about 6 to 10 miles northwest of the 14,410-foot volcano, which is 30 to 45 miles southeast of the Seattle-Tacoma area.

But that could be because the 80 electrical sensors used for the experiment were placed in a 190-mile-long, west-to-east line about 12 miles north of Rainier. So the main part of the magma chamber could be directly under the peak, but with a lobe extending northwest under the line of detectors.


Rainwater can penetrate below the Earth's fractured upper crust, according to a new study.

It had been thought that surface water could not penetrate the ductile crust, where temperatures of more than 300°C and high pressures cause rocks to flex and flow rather than fracture, but researchers have now found fluids derived from rainwater at these levels. 

Fluids in the Earth's crust can weaken rocks and may help to initiate earthquakes along locked fault lines. They also concentrate valuable metals such as gold. The new findings suggest that rainwater may be responsible for controlling these important processes, even deep in the Earth.


It's not a secret that groundwater levels in Texas have declined since the Dust Bowl era - the obvious reasons are what you expect - more population and more food grown to sustain them.

But there are other key contributing factors, and the news isn't all bad, according to a new analysis. The groundwater declines have been most severe in the past four decades, according to Dr. Srinivasulu Ale, Texas A&M  AgriLife Research geospatial hydrology assistant professor in Vernon. 


What is the impact of volcanic sulfate emissions on climate? Researchers have completed the most accurate and precise reconstruction to date of historic volcanic sulfate emissions in the Southern Hemisphere, derived from a large number of individual ice cores collected at various locations across Antarctica and is the first annually resolved record extending through the Common Era - the last 2,000 years of human history.

Reconstructions of the past are critical to creating accurate model simulations used to assess natural versus anthropogenic climate forcing. Such model simulations underpin environmental policy decisions including those aimed at regulating greenhouse gas and aerosol emissions to mitigate projected global warming. 


The earthquakes in central Oklahoma since 2009 are likely attributable to subsurface wastewater injection at a handful of disposal wells -
Oklahoma earthquakes constitute nearly half of all central and eastern U.S. seismicity from 2008 to 2013, many occurring in areas of high-rate water disposal.

These are legacy drilling operations, not modern natural gas fracking.


Tsunami earthquakes are rare but they happen at relatively shallow depths in the ocean. So while are small in terms of their magnitude, they create very large tsunamis, with some earthquakes that only measure 5.6 on the Richter scale generating waves that reach up to 30 feet high when they hit the shore. 

A global network of seismometers enables researchers to detect even the smallest earthquakes. However, the challenge has been to determine which small magnitude events are likely to cause large tsunamis.  New research has revealed the causes and warning signs of these rare tsunami earthquakes, which may lead to improved detection measures. 


Activists who are against natural gas in the United States have invented a variety of problems; flaming tap water, earthquakes, headaches, even that it will cause the earth to deflate.

Good thing they don't live in Norway, where energy extraction by the Nextdrill research project is going thousands of meters into the ground, in order to exploit another of nature's bounties:  tinkering with the Earth’s molten core and radioactive isotopes in the Earth’s crust. The project is drilling down to where temperatures are so high it can be used for district heating and electricity generation.

Two studies  presented today at the Goldschmidt 2014 geochemistry conference in Sacramento show that the movement rate of plates carrying the Earth's crust may not be constant over time. That could provide a new explanation for the patterns observed in the speed of evolution and has implications for the interpretation of climate models.  

The Earth's continental crust is an archive of Earth's history and it is the basis for studies on rock formation, the atmosphere and the fossil record - but it is not clear when and how regularly crust formed since the beginning of Earth history 4.5 billion years ago.