open access

https://hdl.handle.net/2115/54968

Geothermal heat flux into deep caldera lakes Shikotsu, Kuttara, Tazawa and Towada

英語

Deep water

2013-04

SPRINGER JAPAN KK

Limnology

14(2)

129-134

Geothermal heat fluxes into the deepest waters of four caldera lakes were measured. Temperature profiles within the stratification period between July and November 2007 allowed a quantification of the acquired heat. Due to their enormous depth, heat input from the lake bed was locally separated from heat fluxes at the surface. In conclusion, a direct measurement of geothermal heat input could be accomplished. Although enhanced geothermal activity could be suspected in all cases, two lakes showed a geothermal heat flux of 0.29 or 0.27 W/m(2) (Lake Shikotsu and Lake Tazawa), as found in other regions not affected by volcanism, while both other lakes (Lake Kuttara and Lake Towada) showed a greatly enhanced heat input of 1 or 18.6 W/m(2), respectively. In conclusion, within our investigated set, all lakes acquired more heat from the underground than the continental heat flux average. Hence, the heat flux into the lakes from the ground was not dominated by the temperature gradient implied by the inner heat of the earth. Other effects like the general temperature difference of deep lake water and the groundwater or local sources of heat in the underground deliver more important contributions. Obviously the flow of water in the underground can play a decisive role in the heat transport into the deep waters of lakes.

学術雑誌論文

Accepted Manuscript

The original publication is available at link.springerlink.com.

1439-8621

1439-863X