Futurity.org » geophysics

Details of Earth’s core ‘ironed’ out

Katie Neith-Caltech — Tue, 27 Dec 2011 15:28:59 +0000

CALTECH (US) — Researchers have zeroed in on the behavior of iron—a key component of the Earth’s core—by conducting high-pressure experiments to simulate conditions at the planet’s interior.

While it has been known for many years that iron is the main element in the core, many questions have remained about just how iron behaves under the conditions found deep in the earth.

Can computers predict the next tsunami?

Dan Stober-Stanford — Thu, 15 Dec 2011 19:16:19 +0000

STANFORD (US) — Scientists have developed computational models of the earthquake and resulting tsunami that devastated Japan in 2010 in order to predict disasters of the same scale.

When the magnitude 9.0 earthquake struck off the coast of Japan in March, it triggered a tsunami that killed more than 20,000 people and destroyed entire cities. It was the largest earthquake ever recorded in Japan, and the scale of the disaster stunned even geophysicists who specialize in earthquake science.

‘Slam-dunk’ proof of water on Mars

Anne Ju-Cornell — Thu, 15 Dec 2011 00:21:26 +0000

CORNELL (US) — The discovery of a bright vein of gypsum in ancient rock proves that water once flowed underground on Mars, researchers say.

The vein, examined by NASA’s Mars exploration rover Opportunity, is about 16 to 20 inches long and the width of a human thumb, and protrudes slightly higher than the bedrock on either side of it. The vein and others like it are within an apron surrounding a segment of the rim of Endeavour Crater.

Earthquakes: Mega-heat, miniscule space

Richard Lewis-Brown — Tue, 18 Oct 2011 14:05:28 +0000

BROWN U. (US) — In an earthquake, rock surfaces sliding past each other create intense stress and heat—but only in super-small places where the surfaces actually touch.

This intense heating can occur even while the temperature of the rest of the fault remains largely unaffected, a phenomenon called flash heating.

New view of California’s tectonic plates

Richard Lewis-Brown — Tue, 11 Oct 2011 16:09:31 +0000

BROWN (US) — The highest resolution picture ever obtained of southern California’s lithosphere shows its thickness differs markedly, offering new insight into how rifting shaped the area’s terrain.

Rifting is one of the fundamental geological forces shaping the planet, but because it involves areas deep below the Earth’s surface, scientists have been unable to understand fully how it occurs. What is known is that with rifting, the center of the action lies in the lithosphere, which makes up the tectonic plates—including the crust and part of the upper mantle.

Don’t blame clouds for climate change

Keith Randall-Texas A&M — Thu, 15 Sep 2011 15:15:13 +0000

TEXAS A&M (US) — Clouds are not the root cause of climate change, but only amplify global warming brought on by human activity, according to a new study.

Decades of data support the mainstream and long-held view that clouds are primarily acting as feedback, says Andrew Dessler, professor of atmospheric sciences at Texas A&M University.

Mexico quake’s path veered from norm

Deborah Williams-Hedges-Caltech — Mon, 15 Aug 2011 15:06:48 +0000

CALTECH (US) — The El Mayor-Cucapah earthquake that struck Baja California in April 2010 took a divergent route, causing a fault line that remained straight on the surface but was warped and complicated at depth.

In a typical earthquake, the line of intersection between the area where the fault slips and the ground is more complicated at the surface than it is below. Transform plate boundary structures—where two plates slide past one another—tend to be vertically oriented, which allows for lateral side-by-side shear fault motion.

Reef reveals life 265 million years ago

Keith Randall-Texas A&M — Thu, 11 Aug 2011 19:44:15 +0000

TEXAS A&M (US) — Rocks from the fossil Permian Reef in the Guadalupe Mountains of West Texas are offering clues about changes in sea level and marine life 265 million years ago.

The findings of two new studies, published in the journals Proceedings of the Royal Society B and Palaios, reveal effects of environmental change on living systems and provide insight on the distribution of hydrocarbon reservoirs in the Permian Basin, one of the largest petroleum provinces in the U.S.

Stiff sediment caused killer tsunami

Tim Green-U. Texas — Fri, 24 Jun 2011 15:59:59 +0000

U. TEXAS-AUSTIN (US)/U. SOUTHAMPTON (UK) — A thick plateau of hard, compacted sediment was a major factor in the 2004 undersea earthquake off the coast of Sumatra that spawned the deadliest tsunami in recorded history.

Once the fault snapped, the rupture was able to spread up from tens of kilometers below the seafloor to just a few kilometers below the seafloor, much farther than weak sediments would have permitted—allowing it to move a greater column of seawater above it, unleashing much larger tsunami waves.

Map surfaces ice sheet’s underbelly

Tim Green-U. Texas — Thu, 02 Jun 2011 19:57:36 +0000

U. TEXAS-AUSTIN (US) — A high-resolution map uses ice-penetrating radar to reveal some of the largest fjords on Earth at the Aurora Subglacial Basin in East Antarctica.

The map is expected to help scientists improve simulations of the past and future of the Antarctic ice sheet and predict its potential impact on global sea levels.