Last year i was invited to join the Ancient Groundwater Team for research about Umbultuk Cave in East Java. Basically it was bit similar to Hang Son Doong in Vietnam, but way smaller. So, they want to find the hidden path of the cave, where its begin and where its end. Because Engineers believe that Umbultuk Cave has another path that branches off the hidden under hill. So they use Geoelectric instruments to find it. Hundred-thousand years ago, the Umbultuk Cave was sea, and then because of the Geology process it raised up and became hills and cave, no wonder there are so many limestones and coral reef there.
Awesome work, thank you for having me Groundwater Team, Ministry of Public Work 😀