Update: Read the article of The Times of Oman here!
Today at 11:52:50 UTC a magnitude 6.3 earthquake occurred in SW Iran close to the shore in a depth of 10 km. The event was widely felt in Iran and across the NE Arabian Peninsula. Moment tensor solution reveal a thrust mechanism, which is in perfect concordance with the historic seismicity pattern. The event was caused by the convergence of the Arabian and Eurasian plates, that not only built up the impressive Zagros Mountains, but also lead to the formation of the Makran Subduction Zone. Relative plate motions there are as fast as 20 mm/yr in the central part. more
On Monday morning, a M4.7 strike-slip earthquake rocked the Anza area, California. The quake occurred at the San Jacinto Fault Zone and was widely felt. As there are not many people who know the San Jacinto better than Tom Rockwell, I recommend to read this short interview. The LA Times has more info on the quake. more
The following mail reached us today:
“A new International Graduate Summer Course in Iceland 2013:
EARTHQUAKE ENGINEERING AND ENGINEERING SEISMOLOGY
Iceland, 30 May – 21 June 2013
www.earthquake.is
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Today’s post of the Landslide Blog about a rockfall caused by a volcanic earthquake reminds me about something that’s in my mind for years already. Could we use dust deposits as a paleoseismological archive? Dust clouds of all sizes, ranging from tiny to huge, can be associated with seismic shaking, especially in arid and mountainous regions. Here I have collected a few videos I found on YouTube. When large amounts of dust settle they should form a distinctive layer recognizable in the sedimentary record, comparable to volcanic ash deposits. Of course they will be harder to be identified, since the material is the local one. I guess this could be done, similar to turbidites in marine paleoseismology. There are papers that describe changes in the aerosol content in the atmosphere after earthquakes, so why not look for them on earth? more
It’s been a while since the last Friday links, so today’s list is rather long. Of course the Russian meteoroid-meteor-meteorite (yes, in this order!) was an absolutely amazing, though destructive phenomenon. The air blast was registered equivalent to an earthquake of magnitude 2.7. Read Livescience’s article here and read this text to get to know about meteors and seismograms in general. more
Several paleoseismology papers have been published in the latest issue of BSSA (103-1). There’s interesting new data on faults in New Zealand, California, and several regions in China, Taiwan and India. For sure I will read the following papers: more
In the last twelve hours, a series of major earthquakes struck the Santa Cruz Islands. Beginning with the activation of a thrust fault with a M8.0 (M7.9) earthquake, almost fifty aftershocks hit the region. A regional tsunami warning was released short six minutes after the first quake at 1:12 UTC and has now been cancelled.
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We’ve seen several magnitude 6 earthquakes last week. On 28 Januar, a shallow M6.1 strike-slip event occurred in eastern Kazakhstan. A little surprise only, we knew about thrust mechanisms in this area, but of course some strike-slip movements do not change the big picture. Would be interesting to check for surface ruptures. This is, by the way, the study area of our friend and colleague Angela Landgraf. Maybe we can convince her to write something about the paleoseismological background of that area? more
Something many people have been waiting for happened last week. Judge Marco Billi explained his verdict in the L’Aquila case. In a 950 page document he published the so-called “motivazione”, stating that “the deficient risk analysis was not limited to the omission of a single factor, but to the underestimation of many risk indicators and the correlations between those indicators.” This should have been understood by the scientists, but instead they delivered a “superficial, approximate and generic” analysis. more
Annals of Geophysics’ latest Special Issue 55-5 is focussed on Earthquake Geology: Active tectonics in the Mediterranean and Europe: site studies and application of new methodologies. This issue was edited by L. Cucci, P. M. De Martini, E. Masana, and K. Vanneste and contains seven papers. As always, all articles are open access. more