Ishikawa, Jan 13 (NHK) - Researchers say the massive earthquake in central Japan on New Year's Day has caused ground upheavals as high as about four meters.
They made the announcement after surveying areas around Kaiso Port in Wajima City, which lies in the northern part of the Noto Peninsula.
They confirmed a ground upheaval of about 4 meters by comparing water levels before and after the disaster.
The pre-quake level was determined using the location of shells and lugworms on a breakwater.
The researchers also found an upheaval of 3.6 meters in a reef on the port's northern side.
The coastlines of northern Wajima and Suzu city have three-step terraces believed to have been formed in massive quakes over the past 6,000 years.
Group leader Shishikura Masanobu of the National Institute of Advanced Industrial Science and Technology says 4-meter ground upheavals are quite rare.
He points out that the Noto Peninsula was formed by the phenomenon, but it only occurs on this scale once every several thousand years.