Self-Potential Method to Assess Embankment Stability: A Study related to the Sidoarjo Mud Flow - Sungkono, Sungkono; Physics Department, Faculty of Sciences, Institut Teknologi Sepuluh Nopember, Jalan Arif Rahman Hakim, Surabaya 60111 (Institute for Research and Community Services, Institut Teknologi Bandung, 2020)