Featured Research

from universities, journals, and other organizations

Earthquakes Would Rattle Central United States

Date:
May 29, 1998
Source:
United States Geological Survey
Summary:
The bluffs of the Mississippi River -- though they shielded Confederate inhabitants from the bombardments of Yankee gunboats during the Civil War-- will not protect the current residents from the strong ground shaking produced by potential large earthquakes.

BOSTON--The bluffs of the Mississippi River -- though they shielded Confederate inhabitants from the bombardments of Yankee gunboats during the Civil War-- will not protect the current residents from the strong ground shaking produced by potential large earthquakes.

Related Articles


Recent U.S. Geological Survey research reveals that there is little difference between the ground motions recorded on the Mississippi River bluffs relative to the ground motions recorded on the nearby floodplain. This evidence will be presented in the poster, Earthquake Ground Motions in the Central U.S., by Mark Meremonte and other USGS scientists from Golden, Colo., as part of the session, USGS Earthquake Hazards Program, Central and Eastern USA, on Thursday, May 28 from 8:30 a.m. to 12 p.m. in Hall C of the Hynes Veteran's Memorial Convention Center.

Most topographic highs on Earth, such as bluffs, are underlain by rock that is more resistant to erosion than the alluvium -- clay, silt, sand, gravel or similar material deposited by running water -- that generally underlies the adjacent valleys or floodplains. As a rule, seismic waves travel faster through rock than through alluvium. As they travel from high-velocity rock to low-velocity alluvium, seismic waves "pile up" -- like slow-moving traffic on a freeway -- and their amplitudes increase.

The topographic relief of the bluffs along the Mississippi River suggest that the area is also underlain by rock with a high seismic velocity and a corresponding tendency to de-amplify the ground motions of the floodplain.

"Alluvium tends to amplify ground motions relative to those of nearby rock," said Edward Cranswick, geophysicist. "On the other hand, sites underlain by rock experience less shaking than sites underlain by alluvium. Ridges are usually underlain by resistant rock, and therefore they usually shake less than the adjacent valleys underlain by alluvium. According to aftershock studies, sites in the Santa Monica Mountains experienced less than a one quarter of the strong ground shaking experienced by some sites in the adjacent San Fernando Valley that were severely damaged by the 1994 Northridge, California, Earthquake."

As the Nation's largest water, earth and biological science and civilian mapping agency, the USGS works in cooperation with more than 2000 organizations across the country to provide reliable, impartial, scientific information to resource managers, planners, and other customers. This information is gathered in every state by USGS scientists to minimize the loss of life and property from natural disasters, contribute to the sound conservation, economic and physical development of the Nation's natural resources, and enhance the quality of life by monitoring water, biological, energy and mineral resources.

To receive the latest USGS news releases automatically by e-mail, please send a request to listproc@listserver.usgs.gov. Please specify the listserver(s) of interest from the following list of names: water-pr; geologic-hazards-pr; biological-pr; mapping-pr; products-pr; lecture-pr. In the body of the message say subscribe (name of listserver)(your name). Example: subscribe water-pr joe smith.


Story Source:

The above story is based on materials provided by United States Geological Survey. Note: Materials may be edited for content and length.


Cite This Page:

United States Geological Survey. "Earthquakes Would Rattle Central United States." ScienceDaily. ScienceDaily, 29 May 1998. <www.sciencedaily.com/releases/1998/05/980529052117.htm>.
United States Geological Survey. (1998, May 29). Earthquakes Would Rattle Central United States. ScienceDaily. Retrieved January 31, 2015 from www.sciencedaily.com/releases/1998/05/980529052117.htm
United States Geological Survey. "Earthquakes Would Rattle Central United States." ScienceDaily. www.sciencedaily.com/releases/1998/05/980529052117.htm (accessed January 31, 2015).

Share This


More From ScienceDaily



More Earth & Climate News

Saturday, January 31, 2015

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Raw: Rare Clouds Fill Grand Canyon

Raw: Rare Clouds Fill Grand Canyon

AP (Jan. 29, 2015) For the second time in two months, a rare weather phenomenon filled the Grand Canyon with thick clouds just below the rim on Wednesday. (Jan. 29) Video provided by AP
Powered by NewsLook.com
Senate Passes Bill for Keystone XL Pipeline

Senate Passes Bill for Keystone XL Pipeline

AP (Jan. 29, 2015) The Republican-controlled Senate has passed a bipartisan bill approving construction of the Keystone XL oil pipeline. (Jan. 29) Video provided by AP
Powered by NewsLook.com
"Cloud Inversion" In Grand Canyon

"Cloud Inversion" In Grand Canyon

Reuters - US Online Video (Jan. 29, 2015) Time lapse video captures a blanket of clouds amassing in the Grand Canyon -- the result of a rare meteorological process called "cloud inversion." Rough Cut (no reporter narration). Video provided by Reuters
Powered by NewsLook.com
Why Researchers Say We Should Cut Back On Biofuels

Why Researchers Say We Should Cut Back On Biofuels

Newsy (Jan. 29, 2015) Biofuels aren&apos;t the best alternative to fossil fuels, according to a new report. In fact, they&apos;re quite a bad one. Video provided by Newsy
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:

Breaking News:

Strange & Offbeat Stories


Plants & Animals

Earth & Climate

Fossils & Ruins

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile: iPhone Android Web
Follow: Facebook Twitter Google+
Subscribe: RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins