An interesting new project aims on a better understanding of ancient earthquakes in Europe. ArMedEa – Archaeology of the Medieval Earthquakes in Europe (1000-1550 AD) is dedicated to increase our knowledge of medieval seismic events. The 2-years project based at Durham University will focus on archaeological information on quakes, tsunamis and earthquake-induced mass movements. ArMedEa is run by Paolo Forlin (supervised by Chris Gerrard and Dave Petley). The project has just started and already has its own blog. more
The SSA 2014 conference in Anchorage, Alaska is over and so is the post-meeting excursion. Our friend and colleague Gösta was attending this field trip on the environmental effects of the Great Alaska Earthquake of 1964 and he sent us some nice images and a brief description of this trip. This is the second part of his report. more
Two articles dealing with induced (or triggered?) seismicity caught my attention last week. Time came up with a report about “The Seismic Link Between Fracking and Earthquakes“. New studies on that topic had been presented at the SSA annual meeting in Alaska. Basically it’s now possible to link two phenomena: a) The huge increase in shale gas and oil development in Ohio, Oklahoma, and Kansas during the last few years; and b) the huge increase in earthquake activity in Ohio, Oklahoma, and Kansas during the last few years. more
On 4 April, 2010, the El Mayor-Cucapah earthquake occurred in NW Baja California, Mexico. It was magnitude 7.2 strike-slip event, and the (surface) ruptures were distributed over a set of faults in the area, among them the Laguna Salada Fault. The epicentral area was under surveillance by a technique similar to DInSAR – Uninhabited Aerial
Vehicle Synthetic Aperture Radar (UAVSAR). Comparison of images from before and after the M7.2 earthquake revealed that slip occurred not only in the epicentral area and at the Laguna Salada Fault, but also on faults to the north. These findings were recently published by Donnellan et al. (2014). more
The SSA2014 annual meeting took place in Anchorage, Alaska from 29 April – 2 May. Currently the post-meeting excursion on the effects of the Great Alaska Earthquake of 1964 is taking place, and we placed our paleoseismicity-spy Gösta Hoffmann in the group. We hope that no one realizes that he’s a desert geologist and absolutely in the wrong place, but he promised to not wear his Teva sandals in order not be identified. Gösta is Associate Professor at the German University of Technology in Oman (GUtech) and works on coastal change and tsunamis, and particularly on tsunamis in the Arabian Sea. Here is his report from Alaska: more
“Doggerland” refers to a drowned landscape located where the North Sea stretches today. Fishermen have found numerous archaeological artifacts when fishing between the coasts of UK and Denmark/Germany (more or less), which led to the idea that an ancient culture lived in this area when the sea level was lower some thousands of years ago. Archaeological studies and modelling confirmed this hypothesis (e.g., see Coles, 2000 or see this paper with a really cool title: White, 2006). Slowly rising sea levels and/or land subsidence forced our ancestors to move to higher grounds and to finally give up Doggerland at all around 8 ka ago. Jon Hill and his co-authors now added some more spice to this story. At the EGU they presented modelling data which imply that the Storegga tsunami over-ran the remaining islands, and that the end of Doggerland was sudden. more
I still try to catch up with all the amazing new stories on earthquakes, tsunamis and paleoseismology that made it to the media last week. Here is #2 on a reviewed tsunami database for Australia. more
A lot of interesting stories on earthquakes, tsunamis and paleoseismology made it to the media last week – no wonder as the EGU2014 and the SSA meeting took place at the same time. I will try to catch up and I start with tsunami hazard in Israel:
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The San Andreas Fault Observatory at Depth (SAFOD) was one of the most ambitious (and expensive) experiments in the history of active fault research. A borehole was drilled through the San Andreas Fault, 3.2 km deep and 1.8 km in horizontal direction. The borehole was equipped with a number of instruments in order to get data from right where the earthquakes occur, but most of the instruments failed already in 2008 due to the extreme conditions. While analyses of the drill core resulted in some great scientific achievements and enhanced our understanding of fault zones, almost no one seems to have much interest in the in-situ instruments. Or let’s say, no one can pay the necessary amount for re-equipping the hole, millions of dollars… more
