KARAKTERISTIK MIKROTREMOR BERDASARKAN ANALISIS SPEKTRUM, ANALISIS TFA (TIME FREQUENCY ANALYSIS) DAN ANALISIS SEISMISITAS PADA KAWASAN JALUR SESAR OPAK MICROTREMOR CHARACTERISTICS BASED ON SPECTRUM ANALYSIS, TIME FREQUENCY ANALYSIS, SEISMICITY ANALYSIS AT OPAK FAULT AREA (Prodi Fisika, Departemen Pendidikan Fisika, 2017)