Understanding mysterious continental intraplate earthquakes

Oct 12, 2007

A new volume published by the Geological Society of America sheds light on mysterious earthquakes in the interiors of continents. These earthquakes, like those that occur in the central U.S., are what the book's editors describe as "an embarrassing stepchild of modern earthquake seismology." Continental Intraplate Earthquakes: Science, Hazard, and Policy Issues provides a comprehensive overview of these rare but very real global hazards.

The plate tectonics revolution of the 20th century elegantly explained why most earthquakes occur where they do – at Earth's plate boundaries. It didn't explain, however, the occurrence of intraplate quakes and the deformation processes that give rise to them. As a result, geologists studying areas like the central U.S., western Europe, and Australia, don't know what causes these quakes, how often they will happen in the future, and how dangerous they are.

"Progress has been slow and somewhat difficult," said volume editor Seth Stein of Northwestern University, Evanston, Illinois, USA. "Because deformation within plates is slow compared to more rapid plate boundary motions, seismicity is much lower and harder to study."

Stein points out that in recent years important insights are emerging with use of new research techniques and approaches. Space geodesy can measure intraplate deformation. Paleoseismology can extend the somewhat sketchy instrumental record backwards in time. Numerical deformation modeling can be used to test hypotheses regarding stresses.

The emerging picture shows earthquakes moving around among faults, which are active for some time and then become inactive for a long time. The results can be used to develop strategies for mitigating earthquake damage while balancing the resources required with those needed for other societal goals.

In organizing the publication Stein and co-editor Stéphane Mazzotti of the Geological Survey of Canada drew on presentations from a number of meetings and other sources that integrated what has been learned from earthquakes around the world. "Because these earthquakes are relatively rare in any given area, combining data from many areas provides valuable insights," said Stein.

One group of papers addresses where intraplate quakes occur and what causes them. A second group assesses the hazards posed and challenges in estimating probability, size, and shaking. A third group explores public policy issues surrounding cost-effective hazard mitigation.

Source: Geological Society of America

Explore further: Synchronization of North Atlantic, North Pacific preceded abrupt warming, end of ice age

add to favorites email to friend print save as pdf

Related Stories

Hoverbike drone project for air transport takes off

3 hours ago

What happens when you cross a helicopter with a motorbike? The crew at Malloy Aeronautics has been focused on a viable answer and has launched a crowdfunding campaign to support its Hoverbike project, "The ...

Study indicates large raptors in Africa used for bushmeat

4 hours ago

Bushmeat, the use of native animal species for food or commercial food sale, has been heavily documented to be a significant factor in the decline of many species of primates and other mammals. However, a new study indicates ...

'Shocking' underground water loss in US drought

4 hours ago

A major drought across the western United States has sapped underground water resources, posing a greater threat to the water supply than previously understood, scientists said Thursday.

Recommended for you

Scientists stalk coastal killer

7 hours ago

For much of Wednesday, a small group of volunteers and researchers walked in and out of the surf testing a new form of surveillance on the biggest killer of beach swimmers - rip currents.

Fires in Central Africa During July 2014

20 hours ago

Hundreds of fires covered central Africa in mid-July 2014, as the annual fire season continues across the region. Multiple red hotspots, which indicate areas of increased temperatures, are heavily sprinkled ...

User comments : 0