What’s up? The Friday links (9)

While the Japan earthquake has dominated the media obviously, some other news came up in geoscience. A researcher team lead by Ludovic Ferrierè who works at the Natural History Museum in Vienna claims to have proven the first impact crater in central Africa. The Luizi structure in the Democratic Republic of Congo was described in 1919 by a German study, but has not been confirmed as an impact crater for decades. Ferrierè and his team now found shatter cones and shocked quartzes, strongly pointing to an impact.  The crater has a diameter of 17 km and a 350 m high rim, which led the scientists to assume a meteor of 1 km diameter and a velocity of ~20,000 m/s. Continue reading “What’s up? The Friday links (9)”

Liquefaction in Tokyo Central Park

Thanks to Alessandro I came across this incredible video of liquefaction occuring in the Tokyo Central Park during the M9.0 Japan earthquake. We can see a lot of very interesting features. First, cracks are opening, perfectly visible on the paved road and the cobble. Then we see the differential moving along those cracks, they are widening and narrowing and there’s vertical movement as well. Soon, the first ruptures appear in the meadows, despite the soft sediment there. Continue reading “Liquefaction in Tokyo Central Park”

Japan EQ & Tsunami: Environmental Effects

The Japan M9.0 earthquake and the following tsunami are well documented by videos, photographs, sea-level measurements, seismograms etc. But how do we recognize such huge events if they happened some thousands of years ago? If there’s no historical report we would use earthquake environmental effects (EEE) for characterizing the earthquake and paleoseismicity. Let’s look what would be left from a 5000 year old earthquake and tsunami. Continue reading “Japan EQ & Tsunami: Environmental Effects”

Mw9.0 earthquake hits Japan, causes Tsunami (updated – 3)

An earthquake with a magnitude of Mw9.0 has occured 130 km east of Honshu, Japan in a depth of ~25 km. This had been the fourth or fifth strongest earthquake to be recorded by instrumental seismology. The quake caused significant destruction to the Honshu Island and triggered a tsunami that  destroyed a number of harbours. In some places (Sendai), tsunami heights were reported to exceed 10 m. A tsunami warning has been released for wide parts of the Pacific, but in Hawaii only 1 m was observed, therefore the warnings for the US West Coast have been lowered. Continue reading “Mw9.0 earthquake hits Japan, causes Tsunami (updated – 3)”

Where on Google Earth? WoGE #271

I have won my first WoGE on Friday, Florian had a great image of the Okavango delta in Botswana. So I have the great pleasure to host the actual quiz.  The rules are simple: Find out the position of the image placed below (provide coordinates) and give a short description of the geological features in the comments. The first to find out has the honor to host the next quiz on his (geo-) blog. I do not invoke the “Schott rule” since I chose to show only a small detail of the subject of interest. This means: Let the games begin! Continue reading “Where on Google Earth? WoGE #271”

What’s up? The Friday links (8)

The Christchurch earthquake was the main topic of the Geoblogosphere this week. A great analysis on the effects was provided by Dave Petley in his Landslide Blog. Highly Allochthonous reasoned on seismic lensing, Ontario Geofish posted a lot on building security, and countless news sites came up with photos and reports. Frank Taylor, who hosted the GoogleEarthBlog before he left for a sailing trip around the world, was in Christchurch next to the Cathedral when the quake happened. On his Tahina Expedition website he reports on his experiences.

Continue reading “What’s up? The Friday links (8)”

What’s up? The Friday links (4)

The California Geological Survey provides a great online-tool for geoscientist: A fault map of California (Alquist-Priolo-Fault-Zone with all datasets available in PDF and GIS format for free! Start here.

A volunteer panel that assesses earthquake risks in Utah said it examined nearly 130 school buildings in the state and found more than half fail to meet federal earthquake safety guidelines. Bad news from here.

Continue reading “What’s up? The Friday links (4)”