Crustal deformation associated with the Kisakata earthquake in 1804 on the Japan Sea coast, northeast Japan.

Abstract

The Kisakata Earthquake (M 7.1) of 1804 was accompanied by acute crustal upheavals, including the emergence of Kisakata Lagoon, which is located on the Japan Sea Coast W of Mt. Chokai. The writers traced the emerged strandline and used microlandforms, surface geology and historical records to reconstruct the pre-earthquake palaeogeography of the area, in an attempt to clarify the modes of deformation associated with the earthquake. The area in which upheaval associated with the earthquake is evident extends for 25km along the coast. The amounts of upheaval deduced from the elevation of the emerged strandline reach a maximum of 180cm around Kisakata and decrease northwards and southwards with similar average gradients of 0.80% and 0.83% respectively. -from English summary