Featured Research

from universities, journals, and other organizations

Discovery Sheds New Light On Cause Of Earthquakes

Date:
December 14, 2006
Source:
University of Liverpool
Summary:
Research at the University of Liverpool into a large fault zone in the Atacama Desert in northern Chile has produced new insight into how fluid pressure can cause earthquakes.

Research at the University of Liverpool into a large fault zone in the Atacama Desert in northern Chile has produced new insight into how fluid pressure can cause earthquakes.

Scientists have found how fluids, such as water, become sealed within the earth's fault planes for a long period of time. This fluid pressure makes it easier for the earth's plates to move alongside each other, eventually resulting in an earthquake.

Dr Dan Faulkner explains: "The difficulty with predicting earthquakes is that we know so little about how fault planes work. Over the years we have found that even small stresses acting on the earth's plates can cause large earthquakes. For example the Loma Prieta earthquake in 1989 caused massive devastation, yet there was very little stress acting on the plate boundary to cause the quake in the first place.

"In theory, high stresses are needed to cause slip along a fault plane, but if something like pressurised water or gas gets inside the fault then it should act as a kind of cushion, making movement between plates easier and an earthquake more likely. Until now a problem with this theory was that as fluid pressures increased the rocks would crack and the fluids could escape through the cracks, reducing the 'cushion' effect. Our recent study, however, found that much smaller cracks surrounding the fault plane change the stresses acting on the rock, reducing the likelihood of significant cracks forming and allowing the fluid to escape."

The team measured the density of 'microcracks' in the rock near the Chile fault line and applied varying amounts of stress to the rock to see how it responded. They found the 'microcracks' changed the elasticity of the rock, which meant stresses that might normally occur at almost right angles to the fault line rotated to a 45 degree angle instead.

Under normal stresses fluid would build up to such as extent that the rock would break and the fluid would escape, reducing the risk of an earthquake. When stress, however, occurs at a 45 degree angle the rock is less likely to break and the low fluid pressures inside can cause earthquakes.

Dr Faulkner added: "We now need to conduct further study into where these fluids and gases are coming from. Scientists are currently drilling of the San Andreas Fault in California, to help us understand more fully the mechanics of fault zones and how earthquakes occur."

The San Andreas Fault Observatory at Depth (SAFOD) is a deep borehole observatory that will measure the physical conditions under which plate boundary earthquakes occur. Dr Faulkner is one of only two UK scientists who currently have access to rock drilled from the San Andreas Fault, which will be analysed in order to understand fault behaviour.

Dr Faulkner's research is published in Nature Magazine.


Story Source:

The above story is based on materials provided by University of Liverpool. Note: Materials may be edited for content and length.


Cite This Page:

University of Liverpool. "Discovery Sheds New Light On Cause Of Earthquakes." ScienceDaily. ScienceDaily, 14 December 2006. <www.sciencedaily.com/releases/2006/12/061213175137.htm>.
University of Liverpool. (2006, December 14). Discovery Sheds New Light On Cause Of Earthquakes. ScienceDaily. Retrieved October 1, 2014 from www.sciencedaily.com/releases/2006/12/061213175137.htm
University of Liverpool. "Discovery Sheds New Light On Cause Of Earthquakes." ScienceDaily. www.sciencedaily.com/releases/2006/12/061213175137.htm (accessed October 1, 2014).

Share This



More Earth & Climate News

Wednesday, October 1, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Earth Has Lost Half Its Vertebrate Wildlife Since 1970: WWF

Earth Has Lost Half Its Vertebrate Wildlife Since 1970: WWF

Newsy (Sep. 30, 2014) A new study published by the World Wide Fund for Nature found that more than half of the world's wildlife population has declined since 1970. Video provided by Newsy
Powered by NewsLook.com
Seismic Activity Halts Recovery at Japan Volcano

Seismic Activity Halts Recovery at Japan Volcano

AP (Sep. 30, 2014) Rescuers were forced to suspend plans to recover at least two dozen bodies from near the summit of Mount Ontake in central Japan on Tuesday after increased seismic activity raised concern about the possibility of another eruption. (Sept. 30) Video provided by AP
Powered by NewsLook.com
Dolphins Might Use Earth's Magnetic Field As A GPS

Dolphins Might Use Earth's Magnetic Field As A GPS

Newsy (Sep. 30, 2014) A study released Monday suggests dolphins might be able to sense the Earth's magnetic field and possibly use it as a means of navigation. Video provided by Newsy
Powered by NewsLook.com
How To Battle Stink Bug Season

How To Battle Stink Bug Season

Newsy (Sep. 30, 2014) Homeowners in 33 states grapple with stink bugs moving indoors at this time of year. Here are a few tips to avoid stink bug infestations. 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