What Makes A Hot Spring, Hot?

Abstract

Hot springs naturally are groundwater that emerges to the surface after being heated up by geothermal activities. There are various classifications of hot springs according to the surface temperature. Still, in Malaysia, it is referred to as the spring that is higher than an average body temperature or 40 °C and above. Two types of hot spring origin are volcanic and non-volcanic sources. The Quaternary magmatic intrusion of Maria volcanic complex in Sabah is the only volcanic-related hot spring. Meanwhile, Sungai Klah, Ulu Slim, Gadek, and other hot springs in Malaysia originated from regional granite intrusion that slowly cooled down since the Triassic period. In Peninsular Malaysia, there is a geological trend of hot springs distribution based on three different intrusion and localities of granite batholiths: Eastern, Central and Western belts of granite. Tectonically, most of these hot springs are associated with fault zones related to highly fractured and deep-seated fault areas with high permeability host rock, such as Bok Bak Fault. Later it can conduit meteoric water to seep deep beneath the subsurface and be subjected to a high geothermal gradient zone. High dissolved minerals in the hot springs are beneficial for balneotherapy, while the excess heat and brine can be harnessed into electrical energy. The development of geothermal potential in Malaysia is still unhurried compared to our neighbouring countries, for example, Thailand’s Fang Geothermal Power Plant is a non-volcanic hot spring with a sound temperature of 130°C which can generate 300 kW of electricity. Lastly, effort has been made by researchers in gathering the data on hot spring distribution in Malaysia which can be viewed with just a click. A new app is developed for Android user named Malaysia’s Hot Springs that can be freely downloaded from the ‘Apps Store’ in hope that the application can serve as hot springs tourism and publication reference purposes.