Now that the new dates for the 8th PATA Days 2017 in New Zealand are fixed, it is time to bring to your attention an exceptional paper that was already published in 2016. I planned to write a review long time ago, but I just managed to do so now. The paper by Quigley et al. is not only likely to become your favourite read during the long flight to New Zealand, but it will also serve as an extremely valuable contribution to the study of earthquake environmental effects (EEEs) in general. The authors report on, and summarise, the effects that the 2010-2011 Canterbury earthquake sequence had on the environment. The paper is special in many ways: more
A team of Ecuadorian and French geologists has started to map the coseismic effects of the M7.8 earthquake that hit Ecuador on 16 April, 2016. The quake occurred at a depth of about 20 km and caused more than 600 fatalities, mainly in the area near Muisne. Two strong aftershocks of M6.7 and M6.8 shook the epicentral area on 18 May, among hundreds of smaller shocks that were recorded. The mapping is coordinated by the Instituto Geofísico. First results show earthquake environmental effects like liquefaction, mud venting, and surface cracks. Some impressions from the field work can be found here:
http://www.igepn.edu.ec/servicios/noticias/1332-levantamiento-geologico-de-los-efectos-del-sismo-del-16-de-abril-en-la-zona-entre-esmeraldas-y-manta
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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: more
A few weeks ago I spent ten days of field work in the Suusamyr Valley in Kyrgyzstan. In the framework of the EwF Project and COMET a team from Oxford (Eleanor Ainscoe, Austin Elliott, Richard Walker) and Kyrgyzstan (Kanatbek Abdrakhmatov, Azat Moldobaev) re-visited the epicentral area of the 1992 MS7.3 Suusamyr earthquake. This thrust earthquake is quite special for it produced intense and widespread secondary earthquake environmental effects (landslides, rockfalls, secondary ruptures, mud eruptions, etc.), but remarkably short primary surface ruptures only. Actually, surface ruptures of several metres height were found near the Suusamyr river, but limited to few hundreds of metres in length. Some 25 km to the west, another set of surface ruptures appeared, which were only about 1 m in height and less than 3 km long. Here are some impressions from our field work. more
It’s Friday – but instead of the Friday links I have the story of a giant post earthquake debris flow in the Wenchuan area for you. As I already announced in my last post about the field trip to the Wenchuan earthquake epicenter in frame of the International Symposium on Mega-Earthquake Induced Geo-disasters and Long Term Effects in Chengdu, China, I still wanted to blog about the Qipan gully debris flow that we also visited during the field trip. After giving you some background information I will take you on the hike with us. We will first see massive destruction in the residential area and then have a look at the debris flow deposits and some mitigation structures while climbing up the gully. Come on, let’s go! more
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: more
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. more
Imagine you live or work in a seismically active region. Imagine you work on paleoseismology, active tectonics, earthquake engineering and encounter an earthquake. And now imagine you stand in the field examining recent earthquake effects. You soon might think about an easy way to document your data to have it digitized right away! Now you can use your Android smartphone to map, categorize, describe and report Earthquake Environmental Effects (EEE). A new application has been released: Earthquake Geo Survey.
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