geomagnetic electro-kinetograph

Japanese: geomagnetic electro-kinetograph（英語表記）geomagneticelectrokinetograph

This is called dynamic calculation, and is widely used because it is convenient, but it cannot be used in shallow oceans or directly under the equator, where the balance of geostrophic currents is not thought to exist. Another indirect current measurement method is the geomagnetic electro-kinetograph (GEK), which uses the laws of the Earth's magnetic field and electromagnetic induction.
[Influence of ocean currents]
Ocean currents have a huge influence on the climate.

From [GEK]

…Abbreviation of geomagnetic electro-kinetograph. Translated as electromagnetic current meter. …

*Some of the terminology that refers to "geomagnetic electro-kinetograph" is listed below.

Source | Heibonsha World Encyclopedia 2nd Edition | Information

Japanese:

…これを力学計算といい，便利なので多用されるが，地衡流の釣合いが成立していないと思われる浅い海や赤道直下では使えない。このほかに間接測流としてはGEK(geomagnetic electro-kinetographの略)と呼ばれる地球磁場と電磁誘導の法則を利用した海流計も使われる。
［海流の影響］
　海流が気候に及ぼす影響はきわめて大きい。…