We determined earthquake locations through re-picking of P-and S-wave arrival times recorded by BMKG network. Earthquake locations were determined using Hypoellipse code that employs a single event determination method. We then relocated the events using hypocenter double-difference method. We also conducted focal mechanism analysis to estimate the type of fault slip. The results indicate improved hypocenter locations, where patterns of seismicity in West Java were delineated clearly. There are several clusters of earthquakes at depths ≤ 30 km, which are probably related to the Cimandiri, Lembang, and Baribis faults. In addition, there is another cluster in Garut trending southwest-northeast, which is possibly related to a local fault. Histograms of travel-time residuals depict good results, in which travel-time residuals are mostly close to zero. Source mechanism throughout the Lembang fault indicates a left-lateral strike slip in agreement with previous studies. The Cimandiri fault also shows a left-lateral slip, but in the south it shows a thrust fault mechanism. While the source mechanisms of the western part of the Baribis fault indicate a thrust fault and the cluster of events in Garut shows a right-lateral slip if they are related to a local fault.

We present the first continental-scale seismic model of the lithosphere and underlying mantle beneath Southeast Asia obtained from adjoint waveform tomography (often referred to as full-waveform inversion or FWI), using seismic data filtered at periods from 20 to 150 s. Based on >3,000 hr of analyzed waveform data gathered from ∼13,000 unique source-receiver pairs, we image isotropic P-wave velocity, radially anisotropic S-wave velocity and density via an iterative non-linear inversion that begins from a 1-D reference model. At each iteration, the full 3-D wavefield is determined through an anelastic Earth, accommodating effects of topography, bathymetry and ocean load. Our data selection aims to maximize sensitivity to deep structure by accounting for body wave arrivals separately. SASSY21, our final model after 87 iterations across seven period bands, is able to explain true-amplitude data from events and receivers not included in the inversion. The trade-off between inversion parameters is estimated through an analysis of the Hessian-vector product. SASSY21 reveals detailed anomalies down to the mantle transition zone, including multiple subduction zones. The most prominent feature is the (Indo-)Australian plate descending beneath Indonesia, which is imaged as one continuous slab along the 180° curvature of the Banda Arc. The tomography confirms the existence of a hole in the slab beneath Mount Tambora and locates a high S-wave velocity zone beneath northern Borneo that may be associated with subduction termination in the mid-late Miocene. A previously undiscovered feature beneath the east coast of Borneo is also revealed, which may be a signature of post-subduction processes, delamination or underthrusting from the formation of Sulawesi.Plain Language Summary Southeast Asia is one of the world's most tectonically active regions, as evidenced by frequent large earthquakes and volcanic eruptions. We present a large-scale 3-D seismic structural model of this region down to a depth of 800 km that reveals a variety of primary features, including beneath the poorly understood islands of Borneo and Sulawesi. This is possible thanks to the use of a sizable data set of earthquakes recorded by a large number of permanent and temporary stations located in Southeast Asia, and advanced imaging methodology that is better able to capture the true physics of seismic wave propagation compared to more traditional methods. Our new model is capable of resolving variations in seismic properties associated with ongoing subduction (when one tectonic plate descends into the mantle below another plate), particularly along the northern margin of the Australian plate beneath the Sunda Arc. More subtle anomalies associated with remnant subduction, which correspond to plate fragments that remain once subduction stops, can also be imaged. These results are important for achieving a better understanding of the subduction cycle, which plays a central role in plate tectonics, and has important implications for, among other things, the evolut...

The island of Lombok in Indonesia is located between the Indo-Australian and Eurasian subduction trenches and the Flores back-arc thrust, making it vulnerable to earthquakes. On 29 July 2018, a significant earthquake Mw 6.4 shook this region and was followed by series of major earthquakes (Mw>5.8) on 5, 9, and 19 August, which led to severe damage in the northern Lombok area. In this study, we attempt to reveal the possible cause of the sequences of the 2018 Lombok earthquakes based on aftershock monitoring data. Twenty stations were deployed to record earthquake waveform data from 4 August to 9 September 2018. In total, 3259 events were identified using 28,728 P- and 20,713 S-wave arrival times during the monitoring. The aftershock hypocenters were determined using a nonlinear approach and relocated using double-difference method. The moment magnitude (Mw) of each event was determined by fitting the displacement spectrum amplitude using a Brune-type model. The magnitudes of the aftershocks range from Mw 1.7 to 6.7. The seismicity pattern reveals three clusters located in the Flores oceanic crust, which fit well with the occurrences of the four events with Mw>6. We interpret these events as the main rupture area of the 2018 Lombok earthquake sequence. Furthermore, an aseismic zone in the vicinity of Rinjani extending toward the northwestern part of Lombok was observed. We propose that the crust in this area has elevated temperatures and is highly fractured thus inhibiting the generation of large earthquakes. The aseismic nature is therefore an artifact of the detection threshold of our network (Mw 4.6).

Peran MOL sebagai dasar komponen pupuk, mikroorganisme tidak hanya bermanfaat bagi tanaman juga bermanfaat sebagai agen dekomposer bahan organik, limbah pertanian, limbah rumah tangga dan industri. Penelitian ini dilatar belakangi dengan banyaknya limbah buah-buahan yang tidak termanfaatkan, limbah bonggol pisang yang dibiarkan menumpuk tanpa dilakukan pengolahan menjadi lebih bermanfaat, keong mas yang selalu dianggap sebagai hama pada tanaman dan rumen sapi yang terbuang begitu saja dan upaya mengatasi ketergantungan terhadap pupuk dan pestisida kimia dapat dilakukan dengan meningkatkan peranan mikroorganisme. Penelitian ini bertujuan untuk menghasilkan bioaktivator kompos dan mikroorganisme yang terdapat pada mol. bahan yang digunakan dalam pembuatan MOL adalah bonggol pisang, limbah buah-buahan , keong mas, rumen sapi, urin sapi, air kelapa , air cucian beras (leri), terasi, gula merah untuk MOL I sedangkan Untuk MOL II hanya dibedakan dengan menggunakan gula putih. Pembuatan bioaktivator dilaksanakan di Laboratoriuam Produksi Politeknik Pertanian Negeri Samarinda. Bioaktivator dibuat dengan cara difermentasikan. Fermentasi bahan-bahan MOL I dan MOL II pada hari ke sepuluh seluruh permukaan mol telah ditumbuhi oleh benang-benang berwarna putih, dan berbau aroma tape. Sedangkan hasil identifikasi mikroorganismen pada bioaktivator pada kombinasi MOL I terdapat 4 jenis bakteri, yaitu Clavibacter, Agrobacterium, Clostridium, Pseudomonas berfluorescens, sedangkan untuk MOL II terdapat 3 jenis bahteri yaitu Pseudomonas berfluorescens, Erwinia dan ClavibacterKata Kunci : Bioaktivator; mikroorganisme lokal; limbah buah-buahan; bonggol pisangThe role of MOL as a basic component of fertilizer, microorganisms not only beneficial to plants are also useful as decomposers agents of organic materials, agricultural waste, household waste and industry. This research is based on the amount of untreated fruit waste, the waste of banana hump which is left to accumulate without the processing becomes more useful, the golden snail which is always considered as a pest on crops and cattle rumen that just wasted and efforts to overcome the dependence on fertilizer and chemical pesticides can be done by increasing the role of microorganism. This study aims to produce bioactivators of compost and microorganisms found in moles. the ingredients used in the manufacture of MOL are banana sticks, fruit waste, golden snail, cow rumen, cow urine, coconut water, rice laundry water (lery), terrace, brown sugar for MOL I whereas For MOL II only differentiated by using sugar white. Preparation of bioactivators carried out in the Laboratory of Production Polytechnic of Agriculture State of Samarinda. Bioactivators are made by fermentation. Fermentation of MOL I and MOL II materials on the tenth day of the entire surface of the mole has been overgrown with white threads, and smells of tape. Fermentation of MOL I and MOL II materials on the tenth day of the entire surface of the mole has been overgrown with white threads, and smells of tape. While the results of microorganisms identification on bioactivator in combination of MOL I there are 4 types of bacteria, namely Clavibacter, Agrobacterium, Clostridium, Pseudomonas berfluorescens, while for MOL II there are 3 types of Pterudomonas fluorescens, Erwinia and Clavibacter

We reveal the existence of a previously unknown fault that generated the Mw 7.3 Flores Sea earthquake, which occurred on 14 December 2021, approximately 100 km to the north of Flores Island, in one of the most complex tectonic settings in Indonesia. We use a double-difference method to relocate the hypocenters of the mainshock and aftershocks, determine focal mechanisms using waveform inversion, and then analyze stress changes to estimate the fault type and stress transfer. Our relocated hypocenters show that this earthquake sequence ruptured on at least three segments: the source mechanism of the mainshock exhibits dextral strike-slip motion (strike N72°W and dip 78° NE) on a west–east-trending fault that we call the Kalaotoa fault, whereas rupture of the other two segments located to the west and east of the mainshock (striking west-northwest and southeast, respectively) may have been triggered by this earthquake. The Coulomb stress change imparted by the rupture of these segments on nearby faults is investigated, with a focus on regions that experience a stress increase with few associated aftershocks. Of particular interest are stress increases on the central back-arc thrust just north of Flores and the north–south-striking Selayar fault in the northwest of our study region, both of which may be at increased risk of failure as a result of this unusual earthquake sequence.