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.

Earth’s Core Spins Faster Than Surface, Study Confirms

Publication: National Geographic News   Date: August 25, 2005   View Article

Analysis of nearly identical earthquakes that happened years apart proves that Earth’s moon-size inner core rotates faster than the rest of the planet, a team of geophysicists report today.

The finding is “unambiguous” and should settle a nearly decadelong debate over the matter, said Xiaodong Song, a geophysicist at the University of Illinois at Urbana-Champaign.

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.

Can the Moon Cause Earthquakes?

Publication: National Geographic News   Date: May 23, 2005   View Article

Coast dwellers are accustomed to the daily rhythm of the tides, which are primarily lulled in and out by the gentle gravitational tug of the moon. Some scientists wonder whether the moon’s tugging may also influence earthquake activity.

“The same force that raises the ‘tides’ in the ocean also raises tides in the [Earth’s]crust,” said Geoff Chester, an astronomer and public affairs officer with the U.S. Naval Observatory in Washington, D.C.

Tsunami Region Ripe for Another Big Quake, Study Says

Publication: National Geographic News   Date: March 16, 2005   View Article

The earthquake that triggered the December 26 tsunami has increased stress on nearby faults, making another major South Asian quake more likely, scientists reported today.

The magnitude 9 earthquake was centered off the west coast of Sumatra, an Indonesian island. The quake shifted nearly 97,000 square miles (250,000 square kilometers) of terrain along the Sunda trench subduction zone, where the Indonesian and Australian tectonic plates dive beneath the Burma tectonic plate.

Tsunami-Battered Sumatra Ripe for More Disasters

Publication: National Geographic News   Date: January 7, 2005   View Article

The force of the magnitude 9 earthquake that struck northern Sumatra on December 26, 2004, may have caught much of the world by surprise. But scientists say the region has a violent geologic past and is ripe for more cataclysmic earthquakes and volcanic eruptions in the millennia to come.

The Indonesian island sits in an area of the Indian Ocean where several large chunks of Earth’s crust, known as tectonic plates, collide. Tectonic plates can slip past, beneath, and over the top of each other. In the Sumatra region, the Indian and Australian plates are slowly creeping alongside and—in a process called subduction—diving beneath, the Burma plate, part of the larger Eurasian plate.

Coming Soon: Your Local Earthquake Forecasts?

Publication: National Geographic News   Date: September 17, 2004   View Article

In life, few events happen in isolation. Earthquakes are no exception. Scientists are now developing computer models that show how an earthquake in one area can increase or decrease the potential for earthquakes in adjacent areas.

University of California, Davis, computational physicist John Rundle is a member of the QuakeSim project team, a NASA-sponsored initiative to develop the computer models.

© 2008-2010 Collected Writings By John Roach