IRSN report on the Napa Earthquake, California (M6, 2014-08-24)

Our colleagues Stéphane Baize and Oona Scotti from the French IRSN finished a report on the 2014 Napa Earthquake: Post-seismic survey report, with special focus on surface faulting. On 24 August 2014, an earthquake of magnitude Mw6 occurred on the West Napa Fault in shallow depth. The quake caused significant damage, an interesting pattern of surface ruptures, and the immediate attention of hundreds of geologists. The primary and secondary effects were mapped only hours after the event, which turned out to be extremely important – a large amount of afterslip was recorded in the following days. The earthquake was not only recorded by a huge seismometer network, but the ground motion was also captured by GPS sensors and InSAR images. The new IRSN report is especially concerned with the surface faulting hazard, since this agency is responsible for the safety of nuclear installations in France.  Continue reading “IRSN report on the Napa Earthquake, California (M6, 2014-08-24)”

Earthquake Geology sessions at the 16 World Conference on Earthquake Engineering, Chile, 2017

The 16 World Conference on Earthquake Engineering will be held from 9-13 January, 2017, in Santiago de Chile. Note that the deadline for short abstracts submission is 23 November, 2015! Abstracts can be submitted via this link.

This meeting comes with a number of sessions which are interesting for earthquake geologists, paleoseismologists and those of us who deal with seismic hazard assessments. Among them: Continue reading “Earthquake Geology sessions at the 16 World Conference on Earthquake Engineering, Chile, 2017”

Guest blog by Yu Zhou (Oxford): The 2013 Mw 7.7 Balochistan earthquake in Pakistan: NOT SO UNUSUAL

In 2013, a MW7.7 earthquake struck Balochistan, caused a huge surface offset and triggered a small tsunami in the Arabian Sea. Immediately, the apparently strange fault behaviour caused the attention of scientists world wide and a number of papers were published. The discussion is highly interesting and still ongoing. This an interesting case for paleoseismologists, too, not only because of the cascading earthquake effects, but also because of the surface rupture distribution, from which we might learn some important lessons for our future work. Now my colleague Yu Zhou and his colleagues from Oxford University published a new paper on this event, arguing that it might be not as unusual as it seems. Their research is based on the analysis of Pleiades stereo satellite imagery, which has proven to be a very useful data source already. Yu send me a nice summary of his recent research: Continue reading “Guest blog by Yu Zhou (Oxford): The 2013 Mw 7.7 Balochistan earthquake in Pakistan: NOT SO UNUSUAL”

Tectonics from above – RAS discussion meeting

Last Friday the RAS held a discussion meeting on Tectonics from Above: Recent Advances in the Use of High-resolution Topography and Imagery in London. Almost the entire Cambridge Tectonics Group went there and I absolutely enjoyed the meeting and the discussion with friends and colleagues mainly from the UK and from France. The speakers reported on open-source software for producing high-res DEMs, advances in aerial and satellite imagery, new techniques in remote sensing, and latest developments in fault/offset mapping. The meeting was supported by NERC, COMET+ and LICS. Continue reading “Tectonics from above – RAS discussion meeting”

Session at SSA meeting in Pasadena: How reliable are reconstructions and models of surface-rupturing earthquakes?

The SSA 2015 meeting will take place in Pasadena, CA, from 21-23 April. As always, there will be plenty of interesting things for paleoseismologists. Scott Bennett asked me to advertise the following session that deals with a topic most of us will find highly important:

How Reliable Are Reconstructions and Models of Surface-Rupturing Earthquakes?

Abstract deadline is 9 January, 2015. Continue reading “Session at SSA meeting in Pasadena: How reliable are reconstructions and models of surface-rupturing earthquakes?”

GEER report on the Napa earthquake online

The M6.0 Napa earthquake came along with some interesting effects. It produced relatively large surface ruptures, but only minor secondary earthquake environmental effects like localized lateral spread, almost no liquefaction and rockfalls, but some hydrological changes. Dozens of geoscientists went out for mapping the earthquake ruptures, supported by InSAR data that precisely show where the ground moved.

Now the Geotechnical Extreme Events Reconnaissance (GEER) Association published a 400-pages report on their findings. The report is available for download here. Make sure to read it, it’s full of data and great photographs of surface ruptures.

Other interesting articles and posts on the Napa quake: Continue reading “GEER report on the Napa earthquake online”

Fieldtrip guide for download: 4D Architecture of an Oblique Rift Margin – Paleoseismology of the Borrego and Laguna Salada Faults (MEX)

The Friends of the Pleistocene went on a fieldtrip few days ago to study the 4D Architecture of an Oblique Rift Margin in Baja California, NW Mexico. The tour focussed on the paleoseismology of the Borrega and Laguna Salada Faults, especially on the 1982 and 2010 surface ruptures, and took place fom 27 February to 2 March, 2014. You can download the detailed field guide and the road log here. Continue reading “Fieldtrip guide for download: 4D Architecture of an Oblique Rift Margin – Paleoseismology of the Borrego and Laguna Salada Faults (MEX)”

Paleoearthquakes identified in W Nepal – seismic hazard higher than expected?

An interesting paper has been published in Nature Geoscience by Murphy et al.: Limit of strain partitioning in the Himalaya marked by large earthquakes in western Nepal. It doesn’t happen too often that paleoseismological papers are published in this journal and it’s also not too often that authors publish such beautiful photos. The authors identified a more than 60 km long rupture in W Nepal with 10 m of surface offset (strike-slip with a normal component). 14C dating points to seismic activity between AD 1165 and 1400. That’s pretty surprising for many reasons: Continue reading “Paleoearthquakes identified in W Nepal – seismic hazard higher than expected?”