Frictional HeatApril 13, 2012
Chikyu crew testing out frictional heating (courtesy of Charna)
One of the major objectives of JFAST is the measurement of temperature in the fault zone. Why is this important - well, rapidly rub your hands together like the some of the Chikyu crew are doing in the above picture. Your hands start to get warm due to friction. The slip that occurred on the fault during the Tohoku earthquake would have produced a lot of frictional heat. By measuring how the temperature of the fault zone changes with time scientists can estimate the frictional heat produced when the fault slipped. This can then be used to infer information about frictional stress on the fault.
Spring stormApril 6, 2012
We arrived at the drill site on April 3 and shortly there after were met by a large spring storm (Article on storm). We had 30 m/s and 8-10 m high waves. We started seeing WOW on all of the drilling progress updates. Thought it was an exclamation about how big the storm was, turns out it just means "waiting on weather". Really it wasn't that bad on the ship. Some people got seasick on the 4th, thanks to medication I was not among them but I was a little queasy. We weren't allowed out on deck and the elevators and gym were closed. It was pretty cool view from the port window though. There were a lot of white caps and sometimes I could see the separate crests and troughs of the waves passing by the ship but videos and pictures aren't nearly as impressive as the real thing. The storm ended yesterday and we are progressing towards starting to drill!
What is Namazu?April 4, 2012
According to Japanese mythology Namazu is a giant catfish that lives in the mud beneath the islands of Japan. Namazu is restrained by the god Kashima but when Kashima lets down his guard Namazu moves and the result is an earthquake. On March 11, 2011 during the Tohoku earthquake Namazu moved a lot.
Now one year later IODP expedition 343 - Japan Trench Fast Earthquake Drilling Project (JFAST) has set off to study the Tohoku subduction zone on the deep sea scientific drilling vessel Chikyu. The water depth where we will be drilling is 6910 meters below sea level. Chikyu will drill as much as 1000 meters below the seafloor to reach the fault zone. Drilling has never been done to such depths before. We will measure fault zone physical properties, recover material from the fault zone, and record the temperature anomaly that resulted from frictional slip during the Tohoku Earthquake. From this information we will learn more about the fault zone and why it slipped.
Leaving land behind and heading to the drill site located off the Oshika Peninsula.
View of Mount Fuji from the heli deck