BREAKING: White House OSTP Blog - "Understanding Earthquakes"

I just got this link from a USGS tweet.

[link to www.whitehouse.gov]

Understanding Earthquakes and Their Impacts: Part I

Posted by Tammy Dickinson and David Applegate on May 10, 2011 at 10:46 AM EDT

Ed. Note: This is the first of a two-part blog focusing on the science and aftermath of earthquakes. Part I focuses on the science of a high-magnitude earthquake and whether one could happen in the United States. Tomorrow, Part II will focus on What We Can Do About It.

Part I: Could a 9.0 Happen Here?

Four deadly earthquakes in just over a year—Haiti, Chile, New Zealand, and now Japan—have provided sudden reminders of the tectonic forces active beneath our feet. Perhaps more importantly, they serve as reminders that disasters resulting from those earthquakes are not the work of nature alone. Even in the face of such giant forces, societal decisions before and after an earthquake can have a major impact on the amount of damage, lives lost, and other outcomes. So while scientists and engineers share in society’s obligation to help the victims, we have an additional responsibility to learn from these events and share lessons that can be applied to vulnerable communities—not only abroad, but also here in the United States.

To make those wise decisions requires some basic geology. Most people know that the crust of the Earth is broken into about a dozen major sections, or plates, (and a number of smaller ones) that slowly move against one another. And when plates collide, the rock material in the collision zone is strained and eventually either breaks or slips along the boundary, causing an earthquake. Less widely appreciated is that the largest earthquakes occur along plate boundary zones where one plate is driven down beneath another. Most of these “subduction zones” are located around the rim of the Pacific Ocean in what is known as the Ring of Fire, so called because these regions are also particularly prone to volcanic eruptions.

As it turns out, Japan sits on or near the intersection of four of these plates, with the ensuing high risk from earthquakes and volcanoes. The magnitude-9.0 earthquake that occurred on March 11, 2011, was the largest to have struck Japan since seismic recording began 130 years ago and was the fourth-largest earthquake ever recorded worldwide, releasing approximately 1,000 times the energy of the Haiti earthquake of January 2010. In that light it is remarkable that the damage and loss of life was not far greater than it was—a tribute to Japan’s sizable and science-based investments in strict building codes, public preparedness, and earthquake and tsunami early warning systems. In particular, the current estimates of lives lost just from the shaking of this giant earthquake number in the low hundreds. More on this in Part Two of this blog, which we’ll post tomorrow. But it’s important to remember that even as nations begin the humbling process of rethinking certain assumptions about earthquake potential, nuclear safety, and tsunami protection, we must also use the lessons of what went right to redouble ongoing efforts to build resilient communities.

read more:

[link to www.whitehouse.gov]

Last Edited by Account Deleted by User on 05/10/2011 04:29 PM