A devastating tsunami struck Palu Bay in the wake of the 28 September 2018 M w = 7.5 Palu earthquake (Sulawesi, Indonesia). With a predominantly strike-slip mechanism, the question remains whether this unexpected tsunami was generated by the earthquake itself, or rather by earthquake-induced landslides. In this study we examine the tsunami potential of the co-seismic deformation. To this end, we present a novel geodetic data set of Global Positioning System and multiple Synthetic Aperture Radar-derived displacement fields to estimate a 3D co-seismic surface deformation field. The data reveal a number of fault bends, conforming to our interpretation of the tectonic setting as a transtensional basin. Using a Bayesian framework, we provide robust finite fault solutions of the co-seismic slip distribution, incorporating several scenarios of tectonically feasible fault orientations below the bay. These finite fault scenarios involve large co-seismic uplift (>2 m) below the bay due to thrusting on a restraining fault bend that connects the offshore continuation of two parallel onshore fault segments. With the co-seismic displacement estimates as input we simulate a number of tsunami cases. For most locations for which video-derived tsunami waveforms are available our models provide a qualitative fit to leading wave arrival times and polarity. The modeled tsunamis explain most of the observed runup. We conclude that co-seismic deformation was the main driver behind the tsunami that followed the Palu earthquake. Our unique geodetic data set constrains vertical motions of the sea floor, and sheds new light on the tsunamigenesis of strike-slip faults in transtensional basins.
Kebutuhan alat pelindung diri (APD) berupa pelindung wajah mengalami kenaikan yang tajam semenjak penyebaran covid19 . Virus yang dapat menular melalui media droplet tersebut dapat membahayakan tenaga kesehatan atau personal yang berinteraksi langsung dengan penderita penyakit yang disebabkan covid19. Keberadaan pelindung wajah, meskipun bukan alat pelindung satu-satunya sangat diperlukan untuk menunjang peralatan yang lain. Tanpa adanya pelindung wajah tersebut maka akan memperbesar kemungkinan penularan virus tersebut. Tujuan dari penulisan jurnal ini adalah untuk menjelaskan proses desain, pembuatan, serta rencana distribusi APD ke masyarakat. Dari proses yang dilakukan dapat disimpulkan bahwa proses produksi melalui beberapa tahapan yang melibatkan sumber daya manusia dengan kemampuan desain produk, manajerial, pengemasan dan sumber daya alat yang beragam meliputi mesin pneumatic, CNC, alat pemotong dengan laser serta desain komputer. Dari segi distribusi, pengiriman alat dilakukan dengan menggunakan berbagai espedisi darat, laut dan udara dengan area pengiriman beberapa provinsi antara lain Jawa Tengah, Jawa Timur, Jawa Barat, Sumatera Barat serta kepualauan Riau.
A devastating Mw 7.5 earthquake and tsunami struck northwestern Sulawesi, Indonesia on 28 September 2018, causing over 4000 fatalities and severe damage to several areas in and around Palu City. Severe earthquake-induced soil liquefaction and landslides claimed hundreds of lives in three villages within Palu. The mainshock occurred at 18:03 local time at a depth of 10 km on a left-lateral strike-slip fault. The hypocenter was located 70 km north of Palu City and the rupture propagated south, under Palu Bay, passing on land on the west side of Palu City. The surface rupture of the earthquake has been mapped onshore along a 30 km stretch of the Palu-Koro fault. We present results of field surveys on the effects of the earthquake, tsunami and liquefaction conducted between 1–3 and 12–19 of October 2018. Seismic intensities on the Modified Mercalli Intensity (MMI) scale are reported for 375 sites and reach a maximum value of 10. We consolidate published tsunami runup heights from several field studies and discuss three possible interrelated tsunami sources to explain the variation in observed tsunami runup heights. Due to limited instrumentation, PGA and PGV values were recorded at only one of our field sites. To compensate, we use our seismic intensities and Ground Motion to Intensity Conversion Equations (GMICEs) and Ground Motion Prediction Equations (GMPEs) developed for similar tectonic regions. Our results indicate that the maximum predicted PGAs for Palu range from 1.1 g for GMICEs to 0.6 g for GMPEs.
Kebutuhan alat pelindung diri (APD) berupa pelindung wajah mengalami kenaikan yang tajam semenjak penyebaran covid19 . Virus yang dapat menular melalui media droplet tersebut dapat membahayakan tenaga kesehatan atau personal yang berinteraksi langsung dengan penderita penyakit yang disebabkan covid19. Keberadaan pelindung wajah, meskipun bukan alat pelindung satu-satunya sangat diperlukan untuk menunjang peralatan yang lain. Tanpa adanya pelindung wajah tersebut maka akan memperbesar kemungkinan penularan virus tersebut. Tujuan dari penulisan jurnal ini adalah untuk menjelaskan proses desain, pembuatan, serta rencana distribusi APD ke masyarakat. Dari proses yang dilakukan dapat disimpulkan bahwa proses produksi melalui beberapa tahapan yang melibatkan sumber daya manusia dengan kemampuan desain produk, manajerial, pengemasan dan sumber daya alat yang beragam meliputi mesin pneumatic, CNC, alat pemotong dengan laser serta desain komputer. Dari segi distribusi, pengiriman alat dilakukan dengan menggunakan berbagai espedisi darat, laut dan udara dengan area pengiriman beberapa provinsi antara lain Jawa Tengah, Jawa Timur, Jawa Barat, Sumatera Barat serta kepualauan Riau.
The presented reservoir in this paper is a tight carbonate reservoir with vertical and horizontal heterogeneous properties. In particular, the low clay content in this reservoir gives low gamma ray counts, making difficult the layer identification. In addition, the high-resistivity response of hydrocarbon-bearing pay-zones and of the tight layers make more difficult the identification of the reservoir sweet spots. Slim-hole magnetic resonance (MR) logging was deployed in wash-down mode for identifying reservoir sweet-spots for providing lithology-independent porosity and formation fluid characterization. The well placement over a deep elongated anticline with steep dips and the lowering of the production liner are challenging. Consequently, the field is being developed using horizontal wells that cut across multiple reservoir layers to maximize reservoir contact and drainage. MR was acquired with dual wait time enabled T2 polarization to differentiate between moveable water and hydrocarbons. After acquisition, the standard deliverables are partial porosities and permeability index. The porosity is divided into clay-bound water (CBW), bulk-volume irreducible (BVI) and bulk-volume moveable (BVM). The effective porosity, the permeability index and the permeability-effective porosity ratio were used to evaluate the rock quality. The classification was based on the gradient of the permeability-effective porosity ratio, where a steeper gradient is interpreted as high flow zone, a gentle gradient as low flow zone and a flat gradient is considered as tight baffle zone. Based on the MR flow units and fluid types (CBW, BVI and BVM), the drilled interval was classified into six compartments of high flow, one compartment of low flow and five tight baffle zones. Accordingly, the perforation plan was optimized to fit the high flow units only. Comparing to the conventional log analysis, MR excluded approximately 700 ft of non-productive reservoirs, leading to more than 250,000 USD cost savings in perforation, drilling time and production optimization. The well was drilled with a distance-to-bed boundary tool; however, enormous potential exists to use this slim MR tool as a non-radioactive sourceless solution for geosteering through reservoir sweet spots while delivering wells that are more productive safely.
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