Heat that the Earth possesses. The deeper you go underground, the higher the temperature rises, but the geothermal gradient is 1-5°C/100m, and the rate of increase decreases as you go deeper into the Earth. The temperature inside the Earth is said to be 5000-6000°C at depths of 2900km or less. The average heat flow rate of the entire Earth that comes from underground to the surface is about 1.5×10 -6 cal/cm 2・s (1.5HFU). The main sources of geothermal heat are thought to be (1) primordial heat, which is thought to be the residual heat when the Earth was formed, and (2) energy from the decay of radioactive materials. Regional differences in geothermal heat are due to differences in the wide-area geological activity of the region, and heat from volcanoes and hot springs is due to local heat sources of magma near the surface. Generally, areas with a large geothermal gradient and large geothermal flow rate are called geothermal areas, and currently there is active development of geothermal energy to extract this geothermal energy and use it for power generation and other purposes. Source: Encyclopaedia Britannica Concise Encyclopedia About Encyclopaedia Britannica Concise Encyclopedia Information |
地球自身が保有する熱。地下深く入っていくにつれて,温度は上昇するが,この地温勾配は1~5℃/100mで,地球内部にいくに従ってこの増加率は減少する。地球内部の温度は,地下 2900km以下では 5000~6000℃といわれている。地下から地表に出てくる全地球の平均的な熱流量は約 1.5×10-6cal/cm2・s(1.5HFU) 。地熱の原因は,(1) 地球ができたときの余熱と考える始原熱,(2) 放射性物質の壊変によるエネルギーがおもなものと考えられている。地熱の地域的な違いは,その地域の広域的な地質活動の違いによるもので,火山や温泉地帯の熱は地表に近いマグマの局部的な熱源によるものである。一般に地温勾配が大で,地熱流量も大きいところは地熱地帯といわれ,現在ではこの地熱エネルギーを取出して発電や他の方面に用いようとする地熱の開発が盛んである。
出典 ブリタニカ国際大百科事典 小項目事典ブリタニカ国際大百科事典 小項目事典について 情報 |
...Compared to the two species mentioned above, t...
When the term was first used at the end of the 18...
… [Kei Yamazaki]. … *Some of the terminology that...
...The thoracic legs are well developed. The blue...
A contemporary Chinese publisher, editor, and ling...
…(2) Thick soup potage lié: A soup made with boui...
…It is an important rock-forming mineral, a gener...
…Soviet state farms. Abbreviation of sovetskoe kh...
A letter. During the reign of Emperor Zhao of the...
...[Kaneko Kiyotoshi]. . … *Some of the terminolo...
It is also called "hoihonjo." In additio...
… There are two common methods for producing ingo...
…There are horizontal wrinkles at the bends of ea...
...The wings have finely branched veins at the ti...
…[Yoshiharu Imaizumi]. … *Some of the terminology...