Photo/Illutration The coast in Wajima, Ishikawa Prefecture, was uplifted by up to 4 meters in the Jan. 1 Noto Peninsula earthquake. (Provided by Geological Survey of Japan, AIST)

Minoru Matsumura looked sadly at his fishing boat tilting on ground that normally would be underwater at Kaiso port in Ishikawa Prefecture.

“I will have to give up fishing” he said. “Maybe it’s fate.”

The Jan. 1 earthquake caused the ground to rise by up to 4 meters in some areas along the coast of the Noto Peninsula, according to a survey led by the University of Tokyo.

Matsumura, 63, had intended to continue fishing until at least age 70. But it remains unclear when restoration work at the port will begin.

The seabed at Kaiso port, located on the northwest coast of the peninsula, was pushed up in the quake, leaving shells and starfish exposed above the water surface.

“The earthquake has taken away ways of making a living for residents of the Noto Peninsula,” Matsumura said.

Hisaharu Shoji, a 62-year-old fisherman who uses Wajima port on the peninsula’s north coast, was also pessimistic about his future.

He said the ground at the port had risen by more than 2 meters.

“Under these circumstances, the port is no longer usable,” he said.

Shoji, who has been a fisherman since he was 15, after graduating from junior high school, said if the land had sunk in the earthquake, it could have been returned to the former height with additional soil.

“But there is nothing we can do about this uplift,” he said.

His home was damaged in the earthquake.

“My house is a mess, the port is a mess, too. When I see this port, I don’t want to think about the future,” he said.

INCREASE IN PENINSULA’S AREA

The uplift was observed over a wide area along the northern coast of the Noto Peninsula.

An aerial photography analysis conducted by a group with the Association of Japanese Geographers showed the coastline in Wajima moved up to 240 meters toward the sea.

That means the land area of the peninsula expanded by 4.4 square kilometers, equivalent to more than 90 Tokyo Domes.

The New Year’s Day earthquake was caused when the southern side of a fault, where the land of the peninsula is located, rode up over the seaside section of the fault. This action is called a “reverse fault type.”

During the approximately 40 seconds of the fault rupture, the ground was likely uplifted rapidly.

A port on the north coast of the peninsula, where the Japan Meteorological Agency had set up a tidal station to measure tsunami, dried up due to the uplift.

The tidal station was exposed to air, so officials could not obtain tsunami data from it. This is the first time that an uplift has rendered a tidal station inoperable.

The uplift may have mitigated damage from the tsunami that was triggered by the magnitude-7.6 earthquake.

Although the tsunami reached heights of more than 4 meters in Noto town and other areas, significant flooding was not observed on the north coast of the peninsula, according to the geographers group.

The researchers believe that the differences in tsunami damage in each area could be related to the size of the ground upheaval, the pre-quake positions of the ground and the seabed topography.

The group said the effects of earthquake uplifts on tsunami flooding should be a topic for future studies.

Both uplift and subsidence occurred in past earthquakes, including the 1923 Great Kanto Earthquake that devastated the Tokyo area.

After the 2011 Great East Japan Earthquake, subsidence in coastal areas of the Tohoku region is believed to have exacerbated the tsunami damage.

The Cabinet Office said officials take crustal movements at coasts and ports into account when they estimate the potential size of a tsunami, but the phenomenon is not factored into disaster response plans, such as transporting relief supplies.

“We need to review our disaster responses and consider whether we need to make changes in response to Nankai Trough earthquake (off the Pacific Coast) and other disasters,” a Cabinet Office official said.

(This article was written by Tomoyuki Suzuki, Shun Nakamura, Shigeko Segawa and Takahiro Takenouchi.)

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