Jawa, Bali dan NTB merupakan wilayah rawan bencana gempa. Untuk meminimalisasi dampak bencana tersebut, upaya mitigasi perlu dilakukan secara optimal. Salah satunya melalui penelitian hazard kegempaan. Penelitian ini bertujuan untuk menganalisis hazard gempa dan isoseismal daerah penelitian. Tahapan penelitian meliputi studi literatur, pengumpulan dan pengolahan data gempa, pemodelan dan karakterisasi sumber gempa serta analisis hazard gempa dan isoseismal. Analisis hazard gempa dilakukan dengan menggunakan teori probabilitas total dan pemodelan sumber gempa tiga dimensi. Penelitian ini menggunakan katalog BMKG tahun 1903-2010, kedalaman 0-300 km dan Mw ≥5 serta data PGA yang tercatat di jaringan BMKG. Hasil analisis hazard gempa menunjukkan nilai percepatan tanah maksimum

Barru is one of the areas in South Sulawesi where the stratigraphic sequences of lithology from Mesozoic to recent are well exposed. The Tonasa Formation is quite widespread in this area, and it is interesting to find out its various aspects related to the carbonate rock development. For this reason, the distribution of nannofossils were recorded and the relative age of Tonasa Formation was determined using nannofossil collected by measuring section at Barru River. The calcareous nannofossil assemblages are moderate to poor preserved. A total of twenty-three species were identified from the bottom to the top of the interbedded marl and limestone. The nannofossil assemblage-based biostratigraphy of the studied area was shown by the First Occurrence (FO) and Last Occurrence (LO) of the marker species. As for the results, there were six data found in this study, i.e. FO and LO of Reticulofenestra umbilicus, FO of Sphenolithus pseudoradians, LO of Discoaster saipanensis, LO of Calcidiscus formosus, and LO Reticulofenestra bisectus 15 -NN 1 or CP 13 -CN 1a, and equivalent to Middle Eocene until Early Miocene. The result shows important data that will contribute significantly in age constraint of Tonasa Formation.

No abstract

No abstract

Indonesia has a high level of seismic vulnerability because located in the junction area of four large plates, namely the Eurasian plate, Indo-Australian plate, Pacific plate, and Philippine Plate, and also the number of active faults that stretch throughout its regions. One of the efforts to mitigate earthquake disasters is to conduct seismic hazard microzonation efforts. The Research and Development Center of BMKG has carried out ongoing research in the field of seismic microzonation to obtain information on the level of seismic hazard in some regions based on microtremor parameter values, including in the Sukabumi (2009), Bantul (2010), Padang (2011), Cilacap (2012), Kulonprogo (2014), Tasikmalaya (2017), Garut (2018) and Pangandaran (2019). This study tries to prototype the seismic microzonation information system in a web-based spatial information system called InaSMIS (Indonesia Seismic Microzonation Information System). InaSIMS contains information about the analysis of microtremor survey results, including the value of the dominant period (T0), Ground Shear Strain (GSS), and USGS Vs30, which states the level of seismic hazard in an area. InaSMIS is still being developed in the research stage and is not yet an operational service for BMKG. In the future, InaSMIS expected to be a source of public information to determine seismic hazards in Indonesian regions.