Interpreting the strongest deep earthquake ever observed

Dec 04, 2013

Massive earthquakes that strike deep within the Earth may be more efficient at dissipating pent up energy than similar quakes near the surface, according to new research by Wei et al. The authors analyzed the rupture of the most powerful deep earthquake ever recorded.

On 24 May 2013, a magnitude 8.3 earthquake hit deep beneath the Sea of Okhotsk, between Russia's Kamchatka Peninsula and Japan. The main shock of the earthquake was located at 610 kilometers (379 miles) depth, a rupture in the mantle far below the Earth's crust. By inverting seismic waves that were observed during the earthquake, the authors find that this initial shock triggered four subsequent shocks. These four shocks were magnitudes 7.8, 8.0, 7.9, and 7.9. A pressure front from the initial earthquake propagated at a speed of approximately 4.0 kilometers (2.5 miles) per second, setting off three subsequent earthquakes in a line south of the main shock. The rupture of the second follow-up earthquake sent a secondary rupture front back up north, triggering a third aftershock.

In total, the entire earthquake sequence took just 30 seconds, and the bulk of the stress was released by the four major shocks. In similar swarms that occur near the surface, such a release could take hours to days and would likely include a large number of small aftershocks. Based on this, the authors conclude that deep earthquakes are likely more efficient in dissipating stress than shallow earthquakes.

Explore further: Historic climate data provided by Mediterranean seabed sediments

More information: Rupture Complexity of the Mw 8.3 Sea of Okhotsk Earthquake: Rapid Triggering of Complementary Earthquakes? Geophysical Research Letters, DOI: 10.1002/grl.50977, 2013 http://onlinelibrary.wiley.com/doi/10.1002/grl.50977/abstract

add to favorites email to friend print save as pdf

Related Stories

What drives earthquake aftershocks?

Dec 02, 2013

On 27 February 2010 an earthquake of magnitude 8.8 struck South-Central Chile near the town of Maule. The main shock displaced the subduction interface by up to 16 meters. Like usually after strong earthquakes a series of ...

Strong earthquake at exceptional depth

May 24, 2013

This morning at 05:45 CEST, the earth trembled beneath the Okhotsk Sea in the Pacific Northwest. The quake, with a magnitude of 8.2, took place at an exceptional depth of 605 kilometers. Because of the great ...

Old fractures caused rare 8.6 magnitude earthquake

Aug 31, 2012

On 11 April 2012, an 8.6 magnitude earthquake occurred 100 kilometers (62 miles) off the coast of Sumatra. This earthquake was unusual in that it originated within the plate rather than at a plate boundary. In fact, it is ...

Recommended for you

New detector sniffs out origins of methane

9 hours ago

Methane is a potent greenhouse gas, second only to carbon dioxide in its capacity to trap heat in Earth's atmosphere for a long time. The gas can originate from lakes and swamps, natural-gas pipelines, deep-sea ...

The tides they are a changin'

14 hours ago

Scientists from the University of Southampton have found that ocean tides have changed significantly over the last century at many coastal locations around the world.

Lightning plus volcanic ash make glass

Mar 03, 2015

In their open-access paper for Geology, Kimberly Genareau and colleagues propose, for the first time, a mechanism for the generation of glass spherules in geologic deposits through the occurrence of volcan ...

User comments : 0

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.