As the Earth’s tectonic plates shift and grind miles below our feet, we feel the effects on the surface in the form of earthquakes and volcanic activity. As Ed Yong of Not Exactly Rocket Science and Chris Rowan of Highly Allochthonous explain, earthquakes far from tectonic plate boundaries may be aftershocks of more violent seismic events along mid-continental faults that occurred hundreds of years earlier. According to a study published in Nature this week, faults in the middle of a continent take much longer—100 years or more—to return to normal activity; thus, aftershocks can occur long after what would be expected from coastal quakes. In other earthquake news, Chris Rowan also reports on Iran’s decision to move their capital city to a less earthquake-prone location than Tehran. And on Eruptions, Erik Klemetti gets to the bottom of a recent Slashdot post proclaiming that recent volcanic activity in Ethiopia is causing the African continent to rift apart, forming a new ocean. In fact, explains Erik, the recent eruptions are part of a known process. “This is nothing new,” says Erik. “We’ve known that Africa is splitting apart for decades.”
Links below the fold.
- Mid-continent earthquakes are often aftershocks of centuries-old tremors on Not Exactly Rocket Science
- Earthquakes within plates: we don’t know when, and we may not know where on Highly Allochthonous
- Earthquake hazard mitigation the Iranian way on Highly Allochthonous
- <a href="http://scienceblogs.com/eruptions/2009/11/the_rifting_of_africa.php"The rifting of Africa on Eruptions