A new paper on the archaeoseismology of Athens, Greece, was published in the Bulletin of Earthquake Engineering by AMraseys and Psycharis. The authors investigated two classical columns at the Akropolis which survived since classical times and modelled the behaviour of the structures under dynamic (seismic) load. They explain observed damages at the columns and also estimate maximum ground movement that would have toppled the columns. It looks like Old Athens has been relatively lucky in terms of earthquakes in the past, despite it is surrounded by active faults… more
Several new papers were recently published in the fields of tsunami research, tectonics, and liquefaction. Also, a new book on active faults is available. Let’s have a look what can be added to your book shelf or to your Christmas wish list: more
Natural Hazards and Earth System Sciences (NHESS) has just published a new issue with lots of papers on marine and lake paleoseismology. So enough stuff for a good read on a cold and rainy autumn evening. The Special issue was edited by Daniela Pantosti, Eulàlia Gràcia, Geoffroy Lamarche, and Hans Nelson, and is an outcome of the European Science Foundation Research Conference: Submarine Paleoseismology – The Offshore Search of Large Holocene Earthquakes; Obergurgl, Austria, 11-16 September 2010. All articles are availabe for free download! Open access rules! more
Let’s see, this is my 1st post here, thanks again for the invitation. Today, an interesting story circulated through mass and science media. The article by Kremer et al. published yesterday in Nature Geoscience presents geophysical and sedimentological evidence of potential tsunamis in the rather exotic environment of Lake Geneva. This phenomenon is not new at all and has been investigated by others before, but I pretty much share the authors conclusion, that the hazard of tsunami-like events in continental lakes deserves higher attention in the future.
Two papers on man-made earthquakes have been published last week and both have had received media coverage. Especially now, few days after the L’Aquila trial, the public is interested in any earthquake story and so the new findings that severe earthquakes happened due to human action caused some attention. Additionally, it caused me a headache and triggered not an earthquake, but a feeling of anger. Let’s talk about some good examples for bad science communication. more
Nature published three articles on the Sumatra April 2012 mega-strike-slip earthquakes. I am pretty sure that at least one of them will be discussed intensely. Earlier this year, two earthquakes with magnitudes of M8.6 and M8.2, respectively, occurred in the Indian Ocean off Sumatra. The epicentres were close to the epicentral area of the 2004 Christmas event, but further to the SW and entirely on the Indo-Australian plate. This was surprising for many reasons: We did not expect such strong strike-slip quakes, we did not expect them to happen intraplate, and we were surprised by the complex en echelon and orthogonal fault pattern. more
Two new tsunami papers have been published recently, and I am happy to be co-author of one of them. In Hoffmann et al. 2012 we report on our observations along the NE Omani coast between Fins and Sur. We found a ridge of imbricated boulders parallel to the coast, but in heights of several meters above m.s.l. on top of a cliff and dozens of meters inland. Also, extremely large blocks clearly stemming from the cliff were found. We used LiDAR to determine the mass of very large blocks (up to 40 t) and found this method to result in far lower weights than estimated with the classical method. more
The Sparta Fault in Greece is marked by one of the most impressive mountain fronts I’ve ever seen. A huge (yes, huge!) fault scarp has developed, traceable for kilometers; the fault itself is more than 60 km long. Ancient Sparta has been devastated by the last known major (M>7) earthquake that happened at this fault in 464 BC. Now, Papanikolaou et al. have published new data on this fault. They examined how paramaters like throw, segmentation, and catchments vary along strike and created a new seismic hazard map, showing a site-specific long-term recurrence interval of ~1.8 ka (+/- 450 a). more
A new paper has been published online first by Hinzen et al. on their archeoseismological study in Cologne, Germany. During recent archeological excavations, a number of damaged structures from Roman to Medieval times have been discovered and described among them a synagoge, the Praetorium, and a Roman well. Since damaging historical earthquakes are documented for the Lower Rhine Embayment, seismic shaking was a good guess to have caused the observed damage. more
After I came back from one week of holidays I checked the latest papers. Surprisingly, one was by myself! Finally IOP published our work on combined geoscience techniques in the Orkhon Valley, Central Mongolia. We used Georadar, SQUID-gradiometers, capacitive-coupled geoelectrics, octocopter stereoimages, shallow drillings, datings, and archaeological excavations for an geoarchaeological project. Using geophysical, archaeological and geological observations, we assumed a dating in the Turk/Uighur period (6th–9th century AD) and a re-use under Mongolian reign (12th–17th century AD). This would mean that this site is the furthermost walled structure in the peri-urban area of Khar Balgas. more
