Dettifoss waterfall. The waterfall is 44 m high. The river water is rich in suspended sediments and the waterfall volume is the greatest in Iceland.| J-STAGE
Normal fault at Thingvellir. The boundary between the North American plate on the left-hand side and the Eurasian to the right.| J-STAGE
Reykjavik is a smokeless city. Almost 100% of the electricity and the heating depends upon hydropower and geothermal energy.| J-STAGE
Lakagigar fissure eruption. The 1783-84 Laka- gigar eruption resulted in a great famine, due to which Iceland lost 20% of its population.| J-STAGE
Basaltic lava field, the Svartshengi geothermal power plant (right), and the Blue Lagoon (left).| J-STAGE
Valley of Eldgja. The 934-40 Eldgja eruption occurred along a 75 km-long fissure.| J-STAGE
Palagonite ridge formed by subglacial eruption. Langjokull glacier in the background.| J-STAGE
Earth hummock. Earth hummocks are among the periglacial phenomena. The knoll covered with vegetation is |about 0.5 m high.| J-STAGE
Jokulsarlon lagoon. The Breidamerkurjokull glacier has been retreating since about 1920. The lagoon formed at the glacial front shows a yearly increase.| J-STAGE
Gullfoss waterfall. The two-step cataract has a total drop of 32 m.| J-STAGE
Geyser Strokkur. The geyser erupts at 5-10 minute intervals.| J-STAGE
The braided course of the Jokulfell downstream from Hofsjokull.| J-STAGE

Latest Issue

2024 Vol.133 No.6

Uplift of the Outer Beach at the Mouth of the Hakkagawa River, Monzen Town, Wajima City, Japan, Associated with the 2024 Noto Peninsula Earthquake

The 2024 Noto Peninsula earthquake (M 7.6), which occurred at 16:10 on January 1, 2024, caused a significant uplift of the coastline along the northern coast of the Noto Peninsula. A 3.8—3.9 m uplift was confirmed around Kaiso, Monzen Town, Wajima City, based on the distribution altitude of marine organism remains, indicating the old shoreline on the breakwater wall of a fishing port (Shishikura et al., 2024).
Shallow seabed along a 4.5 km-long stretch of coast was uplifted following the earthquake, from the mouth of the Hakkagawa River in Kaiso to Fujihama, via Kuroshima and Takashima. The Kuroshima Fishing Port at the center of the photograph was completely dried up, and an uplift of at least 3 m was confirmed. The shallow seabed at the mouth of the Hakkagawa River, located on the sandy beach coast (from the bottom center of the picture), was uplifted. The shoreline has advanced seaward by about 150 m. Between the old and new shorelines, a slight elevation above the present shoreline (light grey-brown area) and a ditch-like lowland extending inland from it (dark grey-brown area and small water surface area) were observed parallel to the shoreline, suggesting that the bar and coastal trough (Takeda, 2017), comprising the outer beach, were uplifted. Similar uplifted outer beach detachments are observed in the coastal area south of Kuroshima Fishing Port.
Examples of seismic uplifted beaches have been recognized in many places from the presence of wave-cut shelves and notches left on rocky coasts, but there are few descriptions of uplifted sandy beaches, and they are not expected to be preserved for long due to future wave erosion.
Date of photograph: May 22, 2024 Altitude: about 300 m.

(Hiroshi YAGI, Masato SATO and Ryuji YAMADA)

References

[Takeda, I. (2017): Sandy beaches. in Dictionary of Landforms edited by Japanese Geomorphological Union, Suzuki, T., Sunamura, T. and Matsukura, Y., Asakura Publishing, 294-295. (in Japanese)^*]

[Shishikura, M., Namegaya, Y. and Echigo, T. (2024): Fourth report of the urgent investigation of the 2024 Noto Peninsula Earthquake (Coastal uplift). Geological Survey of Japan. (in Japanese)^*]
https://www.gsj.jp/hazards/earthquake/noto2024/noto2024-04.html [Cited 2024/8/16].