Fukui Prefectural Varve Museum (original) (raw)

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Geological museum in Mikatakaminaka, Fukui Prefecture

Fukui Prefectural Varve Museum
Fukui Prefectural Varve Museum is located in Fukui PrefectureFukui Prefectural Varve MuseumLocation of Fukui Prefectural Varve MuseumShow map of Fukui PrefectureFukui Prefectural Varve Museum is located in JapanFukui Prefectural Varve MuseumFukui Prefectural Varve Museum (Japan)Show map of Japan
Location 122-121-1 Torihama, Wakasa, Mikatakaminaka, Fukui Prefecture
Coordinates 35°33′33″N 135°53′50″E / 35.559056°N 135.897278°E / 35.559056; 135.897278
Type geological museum
Director Kazuma Yamane
Public transit access JR West Obama Line Mikata Station
Website http://varve-museum.pref.fukui.lg.jp

Fukui Prefectural Varve Museum is a geological and archeological museum located in Wakasa, Mikatakaminaka District, Fukui Prefecture, Japan. It features varve ranging from 70,000 years ago to the present, as found at the bottom of Lake Suigetsu. The special chairman is Kazuma Yamane.[1][2]

A thin section of varve on display in Fukui Prefectural Varve Museum. Showing evidence of eruption of Kikai Caldera.

A thin section of varve on display in Fukui Prefectural Varve Museum. A higher magnification.

Interior view of Fukui Prefectural Varve Museum. Thin section of varve on display.

Interior view of Fukui Prefectural Varve Museum. Varve and various historical/archaeological evidence are discussed together.

Lake Suigetsu, one of Five Lakes of Mikata, is located in Wakasa Town, Mikatakaminaka District, Fukui Prefecture. It is a brackish water lake, with an area of 4.06 km², a perimeter of 9.85 km, and a maximum depth of 38.0 m, making it the largest among the five. It lacks directly inflowing river which can disturb the precipitate on the lake bottom. Because of this, the sediments annually form varve and then remain undisturbed. In addition, the lack of oxygen in the water at the lake bottom make it inhabitable to lifeforms, which also helps to keep the varve undisturbed. Also, because of a fault running nearby, the lake gradually lowers its altitude and is never filled up with sediments. With these serendipitous conditions combined, the varve found in the Lake Suigetsu is now known as “Miraculous Sediments”.

The investigation of Lake Suigetsu started on 1991. In boring expedition on 2006, it was not possible to recover 70 m-long varve as one continuous core. Therefore the boring was conducted from 4 different spots, each 1 m long at a time. By matching varve patterns between the core samples, a 70 m-long varve was reconstituted. This equals to a 160,000 year-long varve without any discontinuity and was named SG06 (from Suigetsu, 2006). A team of international collaboration members from Japan, UK, and Germany measured the ratio between radiocarbon 14C and stable isotope 12C throughout the layers of the varve and obtained calibration data of radiocarbon dating 11,200 – 52,800 years ago. This result was published in Science[3]. The error of this calibration is estimated to be about 170 years in 50,000. From this precision, the data obtained from Lake Suigetsu is determined to be the world de facto standard of the radiocarbon dating for geological science in International Radiocarbon Conference held in UNESCO Headaquater in France on July 13, 2014.[4][5]

This museum introduces research on the varve in Lake Suigetsu. A thin-sectioned 45 meter-long sample of varve embedded in epoxy is on display.[1] Other exhibitions cover the formation of varve in Lake Suigetsu, varves from around the world, the paleoclimate around Lake Suigetsu decoded from the varve, and other archeoclimatological findings. Some of the exhibitions have QR codes to read explanation. However, at this point, the explanations are given only in Japanese.

Located within Jomon Roman Park, near Lake Mikata, at the mouth of Hasu river. Also located in the park are, Wakasa Mikata Jomon Museum, Jomon Colosseum, Roadside station "Michino Eki, Five Lakes of Mikata" and Fukui Prefectural Satoyama-Satoumi Research Institute.

Visitor Information

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Closed on Tuesdays (except on holidays, in which case it is closed on the following Wednesday) and at the end and beginning of the year. Discount rates apply to a joint ticket with the Wakasa Mikata Jomon Museum.

  1. ^ a b "Official Webpage".
  2. ^ "日経ビジネスオンライン". Archived from the original on 2017-02-10. Retrieved 2018-09-16.
  3. ^ Bronk Ramsey, C.; Staff, R. A.; Bryant, C. L.; Brock, F.; Kitagawa, H.; van der Plicht, J.; Schlolaut, G.; Marshall, M. H.; Brauer, A.; Lamb, H. F.; Payne, R. L.; Tarasov, P. E.; Haraguchi, T.; Gotanda, K.; Yonenobu, H.; Yokoyama, Y.; Tada, R.; Nakagawa, T. (2012). "A Complete Terrestrial Radiocarbon Record for 11.2 to 52.8 kyr B.P." (PDF). Science. 338 (6105): 370–374. Bibcode:2012Sci...338..370B. doi:10.1126/science.1226660. ISSN 0036-8075. PMID 23087245. S2CID 28554111.
  4. ^ "第10回環境サイエンスカフェ 7万本の縞模様と70万粒の花粉-水月湖の土が語る気候変動7万年の歴史 P.12-P.21" (PDF). Hitachi Environmental Foundation HP. Archived from the original (PDF) on 2013-06-26.
  5. ^ "日本人の活躍で5万2800年前まで遡れる年代目盛りが完成 - Scienceが会見". Mynavi News. 2012-10-22. Archived from the original on 2012-10-23.