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. 

The paper is available online from Ed's ResearchGate page.

We've looked through more than 70 papers published both in English and Japanese which discuss geological evidence for the occurrence of past earthquakes and tsunamis along the Nankai Trough, the subduction zone that lies to the south of Honshu, Shikoku and Kyushu. 

A 3-layered tsunami deposit at
Shirasuka (Komatsubara et al., 2008)

Summarising the content and assessing the strengths and weaknesses of the evidence provided from each site, we make a number of conclusions including:

• There are many records that have been proposed as evidence for earthquakes and tsunamis. The quality of these records varies and there's inconsistency over what data is reported. 
• The best records help to constrain the rupture zones of 12 historical earthquakes. 
• While tsunamis may deposit layers of sand, like those seen to the left, other processes like typhoons may leave similar evidence. Future studies need to try to differentiate between these possibilities.
• Currently there's no evidence of past earthquakes bigger than the AD 1707 Hoei earthquake (though this probably struck almost the entire length of the Nankai Trough).