Combined DC Resistivity Survey and Electric Conductivity- Dielectric Permittivity Measurement at Sag Pond near Lembang Fault, West Java, Indonesia

摘要

LembangFaultisanormalfaultsituatedatthesouthernflankofTangkubanParahuVolcanoinWestJavaIndonesia.Thefault'smovementmayhavecausedtheformationofsagpondinthevicinityofitswhichischaracterizedbythesoillayersofthesagpond.Thecharacteristicsofthesoilcanbeexaminedbasedonitselectricalpropertiessuchasconductivity(theinverseofresistivity)anddielectricpermittivity.DirectfieldmeasurementwasconductedusingDC-resistivityWenner-Schlumbergermethodonthesagpondaswellaslaboratoryresistivitymeasurementofcorestakenfromthesagpond.Tworesistivitycrosssectionswereobtainedafterperforming2Dinversionofthedatawhichrevealthattheresistivitydistributionconsistofaresistivelayer(40-60ohm.m)overlyingamediumresistivelayer(30-35ohm.m).Thethirdlayerhasrelativelylowresistivityof16-25ohm.m.Attheintersectionofthesetwolineswetookcoringsamplesdowntodepthof5mbelowsurfaceandmeasuredtheelectricalconductivityanddielectricpermittivityforeach1cmofsampleusingEM-50datalogger.Resultsfrombothfieldandlaboratorymeasurementwereanalysedtogetabetterunderstandingofthesagpond...