Geology

Deep Sea Volcano Erupts on Film – A First

Publication: National Geographic News   Date: May 24, 2006   View Article

Billowing ash plumes, molten sulfur droplets, feisty shrimp feasting on fish killed by noxious gases, red lava jetting from a vent—they’re all part of the action recently filmed at an underwater volcano in the western Pacific Ocean.

The images are the first ever direct observations of an active, submarine arc volcano. These volcanoes grow near trenches that form where one piece of Earth’s oceanic crust slips beneath another.

Magnetic Field Weakening in Stages, Old Ships’ Logs Suggest

Publication: National Geographic News   Date: May 11, 2006   View Article

Earth’s magnetic field is weakening in staggered steps, a new analysis of centuries-old ships logs suggests.

The finding could help scientists better understand the way Earth’s magnetic poles reverse.

Giant Rock Growing in Mt. St. Helens Crater

Publication: National Geographic News   Date: May 9, 2006   View Article

A massive fin-shaped slab of hot rock has recently been seen growing in the crater of Washington State’s Mount St. Helens.

The feature is the seventh such structure to rise in the volcano’s crater since it began slowly erupting in October 2004, say scientists with the U.S. Geological Survey’s (USGS) Cascade Volcano Observatory.

Clear skies following a long, cloudy, wet winter in the U.S. Pacific Northwest recently lifted the veil on this latest formation.

Greenland Glaciers Losing Ice Much Faster, Study Says

Publication: National Geographic News   Date: February 16, 2006   View Article

Due to global warming, glaciers on Greenland are slipping into the ocean twice as fast as they were just five years ago, scientists announced today.

Current estimates already suggest that Greenland is contributing to rising seas. Now it seems that those estimates may have underestimated the melting island’s effect, says Eric Rignot, a glaciologist with NASA’s Jet Propulsion Laboratory at the California Institute of Technology in Pasadena.

Warming surface temperatures in Greenland are allowing more meltwater to trickle down to the glacier bed. There, where glacier meets earth, the water acts as a lubricant, allowing the ice to flow more quickly to the ocean.

2006 Postponed by One (Leap) Second

Publication: National Geographic News   Date: December 29, 2005   View Article

For those of you counting the seconds until 2006, add one.

The world’s top timekeepers will insert an extra second—or leap second—just before midnight in coordinated universal time (UTC) on New Year’s Eve. (That’s the same as 6:59:59 p.m. eastern time on December 31.) UTC is determined by atomic clocks and is five hours ahead of eastern time.

Why Was South Asia Hit Hard by Major Quake

Publication: National Geographic News   Date: October 13, 2005   View Article

The magnitude 7.6 earthquake that shook a broad swath of South Asia on October 8 resulted from the same forces that give rise to the world’s tallest mountains, the Himalaya, experts say.

The Earth’s crust is broken up into a jigsaw puzzle of plates constantly on the move. Some collide, others drift apart. They all jostle along in fits and starts like uncomfortable strangers in a packed crowd.

Sumatra Poised for Another Tsunami, Study Says

Publication: National Geographic News   Date: June 8, 2005   View Article

The earthquake- and tsunami-battered region of Sumatra, Indonesia, is at risk for more temblors and killer waves, seismologists cautioned today in a new study.

Study co-author John McCloskey, a seismologist at the University of Ulster in Northern Ireland, said the finding adds urgency to the push for greater earthquake and tsunami preparedness in the Indian Ocean region.

© 2008-2010 Collected Writings By John Roach