Tuesday, 18 October 2016

A Royal Visit

M. De Batist and V. Heyvaert were part of the Ghent University delegation that accompanied the Belgian Royal Family last week on their State Visit to Japan. At the University of Tokyo, the Ghent University delegation met with the Japanese project partners of AIST and the University of Tokyo, and with the Executive Vice President of the University of Tokyo and discussed the modalities of a cooperation agreement between the University of Tokyo and Ghent University for educational purposes, and of a Letter of Intent between Ghent University, the Royal Belgian Institute for Natural Sciences, the University of Tokyo and AIST for scientific collaboration in geohazard research.

Thursday, 25 August 2016

New paper on the Nankai Trough

The first paper from the QuakeRecNankai project has recently been published in Earth-Science Reviews. We've collated, translated and summarised a wide range of publications which provide evidence for past earthquakes and tsunamis along the Nankai Trough, south central Japan. 

Monday, 16 November 2015

The survey of Lake Kawaguchi is already done !

We finished the coring in Lake Kawaguchi, it was a real success!  Lake Kawaguchi is a shallow lake with a maximum depth of 12 m. It is characterized by three sub-basins – Western, central and East basins. We investigated two sites, one in the western basin and one in the central basin.

Sunday, 8 November 2015

The Fuji Five Lake survey has started !

On Monday, the platform arrived from Hamana-ko to Kawaguchi-ko. At the end of the day, we were ready to core. The aim of the survey is to get long cores from the Fuji Five Lakes in order to retrieve the seismic history of the Nankai Through. During this month, we will investigate Lake Kawaguchi, Lake Motosu and Lake Sai. We will spend one week in Lake Kawaguchi and Lake Sai. Our best target is the Lake Motosu where we will be for two weeks. This year, we decide to not investigate Lake Yamanaka for several reasons. Lake Yamanaka is very close to Fuji volcano and highly exposed to eruptions. The study of the 1998 old borehole revealed a lot of scoria layers and we were not sure that our equipment could go through them. Because our coring system was struck in Hoei scoria (1707A.D.), the age of short cores taken last year is relatively well constrained. In 300 years, Lake Yamanaka has not recorded any turbidites. This is why, this year, we will focus on the other three lakes. In our long cores, we expect to find turbidites triggered by earthquake that allow us to compare the earthquake fingerprint of each lake… But first, we need to hammer!

The platform on Lake Kawaguchi

Thursday, 5 November 2015

Every end is a new beginning

Our working days on coastal Lake Hamana are now definitively over. The platform has been relocated to the Fuji area, where coring operations on Lake Kawaguchi were started.  

Unfortunately, we did not succeed in retrieving all missing core sections on site 3 and site 4 of Lake Hamana, since very strong winds threw a spanner in the works and we were not able to sail out during the last two days. Nevertheless, we now possess sediment samples up to a depth of 9 m below the lake floor, from four different locations along a N-S transect throughout the central basin. Such transect allows us to map the extent and lateral variations of tsunami deposits, which will be traced by executing a series of sedimentological, geophysical and geochemical analyses.

But first… our cores have to be shipped back to Belgium. This will be done at the end of November, after the Fuji survey is finished as well.

Sneak peaks of Mount Fuji from Lake Hamana

Sunday, 25 October 2015

Entering the last week

Having the checkered flag of our Lake Hamana piston coring mission in sight, we can already look back at many days of hard work and dedication. However, we still need to complete a few things.

We have been sampling sediment from four consecutive sites along a N-S transect within the lake’s central basin, north of the tidal delta. Two of these sites are entirely finished (site 1 and 2), whereas we still have to take six more 2 m piston core sections from the northern two sites (site 3 and 4).   

Location map of Lake Hamana (left) and bathymetry of the lake basin with indication of our coring sites, yellow ones are finished, red ones still need to be completed (right)

Sunday, 18 October 2015

If I had a hammer…

I’d hammer in the morning, I’d hammer in the evening…

Two weeks have passed since we started taking cores from our platform on Lake Hamana and loads of mud and sand has been lifted out of the lake floor. Our Belgian coring team is starting to work like a well-oiled machine. Hence, about time to introduce you to our floating home and how we manage to sample more than 8 m of bottom stratigraphy.

Our platform is held in position by four anchors and consists of four rubber floaters, a 3x4 m standing surface with a central opening and a tripod to which three winches are fastened. Each of these winches holds part of the coring equipment, which is guided through pulleys at the crest of the tripod. One winching cable is attached to the hammer weight, one to the piston and one to the entire system (coring barrel, hammer weight and piston).

Leaving the marina