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"In this research the model of earth layers between earthquake's epicenter in Hokkaido Japan and observation station in Black Forest of Observatory (BFO), Germany is investigated. The earth model is 1-D that represents the average speed model. The earth model is obtained by seismogram comparison between data and synthetic seismogram in time domain and three components simultaneously. Synthetic Seismogram is calculated with the Green's function of the Earth by MINor Integration (GEMINI) program, where program's input is initially the earth model IASPEI91, PREMAN and also the Centroid Moment Tensor (CMT) solution of the earthquake. A Butterworth low-pass filter with corner frequency of 20 mHz is imposed to measured and synthetic seismogram. On seismogram comparison we can find unsystematic discrepancies, covering the travel time and waveform of all wave phases, namely on P, S, SS wave and surface wave of Rayleigh and Love. Solution to the above mentioned discrepancies needs correction to the earth structure, that covering the change of earth crust thickness, the gradient of �?�h and value of zero order coefficient in �?�h and �?�v in upper mantle, to get the fitting on the surface wave of Love and Rayleigh. Further correction to accomplish the discrepancies on body waves is conducted on layers beneath upper mantle down to depth of 630 km, where a little change at speed model of P and S wave is carried out. The number of oscillation amount especially on Love wave is influenced by earth crust depth earth. Good fitting is obtained at phase and amplitude of Love wave, but also at amplitude of some body wave too. This effect is not yet been exploited for the determination of moment tensor."

"Gempabumi yang terjadi akibat pelepasan energi di dalam permukaan bumi akan menghasilkan penjalaran gelombang seismik. Gelombang tersebut akan terekam oleh stasiun penerima yang nantinya dilakukan pemrosesan data sebagai kebutuhan interpretasi dari seismogram. Pada proses pengolahan data salah satunya yaitu penentuan waktu tiba gelombang. Penentuan waktu tiba dari gelombang primer dan sekunder masih dilakukan dengan cara manual oleh operator sehingga memiliki kekurangan seperti waktu yang lama, tingkat subjektivitas yang tinggi dan hasil akurasi yang rendah. Pada penelitian ini dilakukan inovasi dalam penentuan arrival time dengan pendekatan deep learning yaitu menggunakan algoritma Convolutional Neural Network (CNN) dan Long Short Term Memory (LSTM). Program yang dibuat dengan menerapkan kedua algoritma ini akan dilakukan pengujian terhadap data lain. Hasil uji pada program yang sudah dibuat kemudian dilakukan komparasi pada hasil picking dari IRIS Wilber. Uji yang dilakukan menggunakan data dari gempa Palu 28 September 2018. Hasil uji dari program komputer yang dibuat dengan perbandingan picking hasil IRIS Wilber memberikan rata-rata eror sekitar 0.005 dan komparasi waktu dari origin time memiliki perbedaan sekitar 2 detik. Program ini sudah menghasilkan hasil prediksi yang cukup akurat.

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Earthquakes that occur due to the release of energy in the earth's surface will result in the propagation of seismic waves. These waves will be recorded by the receiving station which will later be processed as a result of the interpretation of the seismogram. One of the data processing processes is determining the arrival time of the waves. The determination of the arrival time of the primary and secondary waves is still done manually by the operator so that it has drawbacks such as a long time, a high degree of subjectivity and low accuracy. In this study, innovation was carried out in determining arrival time with a deep learning approach, namely using the Convolutional Neural Network (CNN) and Long Short Term Memory (LSTM) algorithms. Programs created by applying these two algorithms will be tested on other data. The test results on the program that has been made are then compared to the picking results from IRIS Wilber. The test was carried out using data from the Palu earthquake on 28 September 2018. The test results from a computer program made with a comparison of IRIS Wilber's picking results give an average error of around 0.005 and a comparison of the time from the origin time has a difference of about 2 seconds. This program has produced predictive results that are quite accurate."

"In this research the S speed structure is investigated by seismogram analysis of Washington's earthquake, C022801L using data of TUC station, Tucson, Arizona, U.S.A. The seismogram comparison between the observed and the synthetic seismogram is conducted in time domain and three components simultaneously. The initially input for the calculation of synthetic seismogram is earth model of PREMAN and CMT solution from the earthquake. A low-pass Butterworth filter with corner frequency of 20 mHz is convolved to observed and synthetic seismogram. Waveform comparison shows a real deviation when travel time and waveform of some wave phase are compared, namely on S wave, surface wave of Love and Rayleigh and wave ScS and ScS-2. This research shows, how sensitive the waveform is to the earth model, better than the method of travel time or the dispersion analysis. Research hereinafter is addressed to finish the found discrepancies at S wave, surface wave of Love and Rayleigh and ScS and ScS-2 wave, in observation station TUC. To obtain the seismogram fitting, correction for S speed structure in earth model is needed, that are changes of earth crust thickness, the speed model of  in upper mantle covering the speed gradient of h and value of zeroeth order coefficient for the h and v, for accomplishing the discrepancies at surface wave of Love and Rayleigh. Further correction on S speed is conducted to accomplish the deviation at S wave at earth layering systems from Upper Mantle up to a 630 km depth. Mean while for the ScS and ScS-2 wave phase the correction is carried out on S speed in the earth layers up to CMB. Fitting Seismogram is obtained at waveform of various wave phases that is S wave, surface wave of Love and Rayleigh and ScS, ScS-2 wave, either on travel time or especially also at oscillation number in Love wave. This result indicates that the anisotropy is occurred not only in upper mantle but till deeper earth layers, till CMB."

"Penelitian ini menginvestigasi struktur kecepatan S di Lautan Hindia melalui fitting seismogram, akibat gempa C081499A, Sumatra Selatan dan direkam di stasiun RER, Pulau Reunion, Perancis. seismogram observasi dibandingkan dengan seismogram sintetik dalam domain waktu dan ketiga komponen kartesian secara simultan. Seismogram sintetik dihitung dengan program GEMINI, dimana input awalnya adalah model bumi global Ocean dan PREMAN. Selain itu pada kedua seismogram dikenakan low-pass filter dengan frekuensi corner pada 20 mHz. Analisis seismogram menunjukkan penyimpangan yang sangat kuat pada pengamatan atas waktu tiba, jumlah osilasi dan tinggi amplitudo, pada gelombang permukaan Love dan Rayleigh dan gelombang ruang S. Untuk menyelesaikan simpangan yang dijumpai diperlukan koreksi atas struktur bumi meliputi ketebalan kulit bumi, gradien kecepatan βh dan besar koefisien-koefisien untuk βh dan βv di upper mantle, dan sedikit perubahan pada kecepatan S di lapisan-lapisan bumi hingga kedalaman 400 km. Fitting seismogram diperoleh dengan baik pada waveform fase gelombang, baik waktu tempuh osilasi utama dan jumlah osilasi. Hasil riset ini menunjukkan, bahwa daerah Lautan Hindia mempunyai koreksi atas struktur kecepatan S dengan nilai positif terhadap model lautan. Hasil ini berbeda dengan hasil riset seismologi lainnya.

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The research investigated the S speed of earth structure under Indian Ocean using seismogram fitting, due to the C081499A earthquake, South Sumatra and recorded in the observation station RER at Reunion Island, France. The observed seismogram is compared to its synthetic in time domain and three cartension components simultaneously. Synthetic seismogram is calculated with the GEMINI program, the initial inputs are the global earth models of Ocean and PREMAN. Prior to seismogram comparison, a low-pass filter with corner frequency of 20 mHz is imposed. The result of analysis shows a very strong deviation at the arrival time, oscillation amount and amplitude height of Love and Rayleigh surface waves and S body wave. To overcome the found discrepancies a correction to the earth structure is needed covering the earth crust thickness, speed gradient of βh and zero-order coefficient for the βh and βv in upper mantle, and a little change in S speed in earth layers down to a depth of 400 km. Seismogram fitting is better obtained at waveform of the wave phase, either the travel time or oscillation number of S wave and Love surface wave. The results shows that the Indian Ocean has correction to the S speed structure, which is positive to standard earth model. This result differs from other seismology research."

"Makalah ini memaparkan hasil pengembangan beberapa model acuan untuk menentukan jumlah stasiun pencatat percepatan gempabumi kuat pada tingkatan negara berdasarkan kondisi geografis, demografis, dan sosial-ekonomi. Beberapa model ini dapat digunakan dalam pengembangan lebih lanjut sistem pencatat gempa bumi kuat Indonesia. Dasar pengembangan model adalah sistem serupa di Selandia Baru, Jepang, Taiwan, Iran, Turki, dan Italia. Parameter jumlahstasiun pencatat yang diusulkan adalah jumlah stasiun per 1000 km2luas daratan, dan tiga buah model regresi eksponensial telah dikembangkan berdasarkan fungsi kepadatan penduduk negara, fungsiProduk Domestik Bruto (PDB) per kapita, dan fungsi Indeks Daya-Saing Global (GCI) kelompok Persyaratan Dasar. Berdasarkan tiga modelini, jumlah minimum stasiun pencatat yang dibutuhkan adalah sekitar 750 stasiun.

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AbstractAn empirical study to develop benchmark models at country-level to assess the suggested number of earthquake strong-motion stations based on a framework encompassing geographic, demographic, and socio-economic parameters is reported. The models are to provide a working estimate of the required number of stations for improving the strong-motion instrumentation program of Indonesia. National earthquake strong-motion networks of New Zealand, Japan,Taiwan, Iran, Turkey, and Italy were used as the references.The parameter proposed is the number of stations in land area of 1,000 km2, and three models based on the exponential regression analysis are presented as functions of population density, Gross Domestic Product (GDP) per capita, and the Global Competitiveness Index (GCI) Basic Requirements Index. Using the models, it is suggested that Indonesia would require at least 750 stations."

"Tinjauan karakteristik zona seismogenik terkait dengan proses rupture gempabumi di zona Subduksi Sumatera telah dilakukan dengan berbagai metode. Zona ini tercatat pernah mengalami beberapa gempa besar yaitu gempabumi Aceh 2004 Mw=9,1, Nias-Simeulue 2005 Mw=8,6, Bengkulu 2007 Mw=8,5, dan Enggano 2000 Mw=7,9. Penelitian ini memfokuskan hubungan antara analisis kontras densitas berdasarkan data gravitasi satelit GOCE dengan distribusi slip di zona rupture empat gempabumi besar yang pernah terjadi. Pemrosesan data gravitasi satelit dilakukan untuk mendapatkan data Gravity disturbance (Gd) dan turunan vertikal gravitasi (Tzz) yang dikoreksi oleh efek topografi dan sedimen dengan dekomposisi spektrum yang berbeda-beda untuk mendapatkan peta gravitasi dengan kedalaman yang berbeda-beda. Berdasarkan analisis Tzz, slip maksimal rupture gempabumi berkorelasi dengan pola Tzz minimal dan kontras densitas rendah, sementara itu rupture berakhir pada pola Tzz maksimal dan kontras densitas tinggi. Pola Tzz dan Gravity disturbance dapat menggambarkan posisi barrier dan asperitas dari zona subduksi Sumatra. Peta skematik berhasil menggambarkan segmentasi seismik Subduksi Sumatra yang memiliki zona asperitas sepanjang strike subduksi yang berhubungan dengan Tzz minimal dan berhubungan dengan zona forearc, serta adanya barrier yang berhubungan dengan Tzz maksimal yang merupakan manifestasi dari struktur (fracture zone dan seamount) yang tersubduksi ke lempeng samudra.

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The review of the characteristics of the seismogenic zone associated with the earthquake rupture process in the Sumatra Subduction Zone has been carried out by various methods. This zone has experienced several major earthquakes, namely the Aceh 2004 Mw=9,1, Nias-Simeulue 2005 Mw=8,6, Bengkulu 2007 Mw=8,5, and Enggano 2000 Mw=7,9. This study focuses on the relationship between density contrast analysis based on gravity data from the GOCE satellite and the slip distribution in the rupture zones of four major earthquakes that have occurred. Satellite gravity data processing was carried out to obtain data for Gravity disturbance (Gd) and vertical gravity derivatives (Tzz), which are corrected by topography and sediment effects with different spectrum decomposition to get gravity maps with different depths. Based on the Tzz analysis, the maximal slip of the earthquake rupture is correlated with the minimal Tzz pattern and low-density contrast. In contrast, the rupture ends at the maximum Tzz pattern and high-density contrast. Tzz pattern and Gravity disturbance can describe the barrier position and asperity of Sumatra subduction zone. The schematic map succeeds in portraying the seismic segmentation of Sumatra Subduction which have asperities zone along the subduction strike associated with the minimal Tzz and associated with the forearc zone, as well as the barrier related to the maximum Tzz which is a manifestation of structures (fracture zone and seamount) that are subducted to the oceanic plate."

"Gempabumi yang terjadi di Yogyakarta 27 Mei 2006 merupakan gempabumi besar dengan kekuatan Mw : 6, 2. Selain menyebabkan kematian sekitar 5000-an jiwa, juga mneyebabkan kerusakan infrastruktur serta mengakibatkan kerusakan geologi berupa hilangnya kekuatan tanah atau likuifaksi. Penelitian ini ingin mengungkapkan kaitan kejadian likuifaksi dengan geologi dan indeks keburukan likuifaksi serta pola wilayah bahaya likuifaksi di Daerah Istimewa Yogyakarta menggunakan metode deskriptif dengan pendekatan spasial (keruangan). Hasil penelitian menunjukkan sebaran titik kejadian likuifaksi cenderung mengelompok di tengah wilayah penelitian, sebarannya mengikuti : sebaran jenis batuan endapan Gunungapi Merapi muda, sebaran umur batuan kuarter. Seluruh titik kejadian likuifaksi dijumpai pada jarak kurang dari enam kilometer dari sesar utama dan sesar minor. Sebaran kejadian likuifaksi tidak selalu dijumpai pada wilayah dengan nilai LSI yang besar. Wilayah bahaya likuifaksi terbagi menjadi : wilayah bahaya likuifaksi sangat tidak aman, tidak aman, dan wilayah aman.

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The Yogyakarta earthquake of May 27, 2006 has magnitude Mw : 6,2. This earthquake caused about 5000 died people and destroyed infrastructures also liquefaction. Focus of this study is interrelation between liquefaction occurance and geological condition and liquefaction severity index (LSI). This research is descriptive and spatial approach. The research shows that distribution of liquefaction occurrence is clustered in the centre part of Yogyakarta Special Province, it is related to young volcanic deposits of Merapi Volcano distribution and Quarternary deposits distribution. Liquefaction occurance is situated within 6 km distance from the major and minor fault zone.The distribution of liquefaction occurance it isn?t related to liquefaction severity index (LSI)."