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Identifikasi Sistem Panas Bumi Di Desa Masaingi Dengan Menggunakan Metode Geolistrik

Online Journal of Natural Science FMIPA Vol 1, No 1 (2012)
Publisher : Online Journal of Natural Science FMIPA

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Abstract

Geoelectric resistance method of Wenner configuration has been used to identify the type and distribution of geothermal  systems located in  the village of Masaingi.  Measurements  were taken around the hot springs in the village of Masaingi, at Sindue District, the Regency of Donggala. The Processing and modeling data using EarthImager 2D software in the form of 2D cross-section. Based on the 2D modeling, it is obtained the resistance type values of hot water layer, ranging from 2-25 Ωmeter.

Analisis Struktur Bawah Permukaan Dengan Menggunakan Metode Seismik Refraksi Di Universitas Tadulako

Online Journal of Natural Science FMIPA Vol 1, No 1 (2012)
Publisher : Online Journal of Natural Science FMIPA

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Abstract

The method is one of the seismic refraction geophysical methods that can be used to determine the structure of the subsurface. The purpose of this study was to to determine the subsurface structure in the area Tadulako University. In this method, the waves generated on the surface of the Earth that will reach down into the surface of the soil or rock, then disuatu point of the boundary between two layers of rock wave is reflected back to the surface and partially transmitted down some refracts due to changes in rock density. Wave propagation below the surface will be detected by the geophones. Aqusisi and data processing method Intercept Time. Data processing is done in 2 stages, using the program and program pickwin Plotreva. The end result of this data processing is the image of the subsurface profile Tadulako University of 6 stretch consisting of three layers of the same. The first layer has a wave speed (V1) 300 m/s are expected mixing of sand gravel dominated by gravel, the second layer has a wave velocity (V2) 1000 m/s are suspected of mixing sand gravel dominated by sand and the third layer has a velocity 2000 m/s are expected mixing of sand and clay.

Pemodelan Tumpahan Minyak di Teluk Lalong Kabupaten Banggai

Online Journal of Natural Science FMIPA Vol 3, No 2 (2014): Volume 3 Number 2 (August 2014)
Publisher : Online Journal of Natural Science FMIPA

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Abstract

Oil distribution  cause environmental problems that disrupt marine ecosystems and reduce the aesthetic value of coastal waters in Gulf  Lalong Banggai. The aims of this study to build a 2D hydrodynamics model to see the patterns  of water mass movement and models of oil spill distribution base on the hydrodynamic models in Gulf of Lalong Banggai Regency (0°5717,3 "latitude and 122 ° 4752 " E) with a potential spill, location, volume, and duration of discharge of oil spills. Based on the results of models oil spill distribution in Gulf Lalong Banggai such us waters prone to oil spills.

Pemodelan Tumpahan Minyak di Teluk Lalong Kabupaten Banggai

Online Journal of Natural Science FMIPA Vol 3, No 2 (2014): Volume 3 Number 2 (August 2014)
Publisher : Online Journal of Natural Science FMIPA

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Abstract

Oil distribution  cause environmental problems that disrupt marine ecosystems and reduce the aesthetic value of coastal waters in Gulf  Lalong Banggai. The aims of this study to build a 2D hydrodynamics model to see the patterns  of water mass movement and models of oil spill distribution base on the hydrodynamic models in Gulf of Lalong Banggai Regency (0°5717,3 "latitude and 122 ° 4752 " E) with a potential spill, location, volume, and duration of discharge of oil spills. Based on the results of models oil spill distribution in Gulf Lalong Banggai such us waters prone to oil spills.

Analysis of the levels of heavy Metal in refill using Atomic Absorption Spectrophotometry (AAS)

Gravitasi Vol 14, No 1 (2015)
Publisher : Gravitasi

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Abstract

Research on determining the levels of lead (Pb), iron (Fe) and manganese (Mn) in refill drinking water at 3 depots in Palu city, namely Manimbaya’s depot, KH Dewantoro’s depot and Tombolotutu’s depot, has been conducted. The determination of metal concentration was analyzed using Atomic Absorption Spectrophotometry (AAS). Results of this analysis show that the iron (Fe) concentrations were 0.1278 mg/L, 0.1426 mg/L, and 0.1059 mg/Lat the Manimbaya’s depot, KH Dewantoro’s and Tombolotutu’s, respectively. Similarly, the manganese (Mn) concentrations were0.1927 mg/L, 0.1240 mg/L, and 0.1538 mg/L at Manimbaya’s depot, KH Dewantoro’s, and Tombolotutu’s, respectively. Keyword: Refill drinking water, metal of lead (Pb), metal of iron (Fe), metal of Manganese(Mn), Atomic Absorption Spectrohotometry (AAS).

Determination ofCoherenceandPhaseDifferencebetween Wind versus Current60 mand Current 60 mversusCurrent 100 mUsingCrossCorrelation in OmbaiStrait, East Nusa Tenggara

Gravitasi Vol 13, No 1 (2014)
Publisher : Gravitasi

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Abstract

Abstract   Data analysis was performed to see coherence and phase difference between the wind versus current 60 m and current 60 m versus current 100 m using cross correlation in Ombai Strait, East Nusa Tenggara. Velocity components U and V of wind and current of wind data and the current were filtered in order to obtain new data on the initial data at any position of t from xt-n  to xt+n. Energy spectrum density of the filter result is determined to examine the fluctuations of wind energy and real currents. Cross-correlation between wind versus current 60 m and current 60 m versus current 100 m is to determine the coherence and the phase difference of the data with the same time interval. Low coherence values in the cross-correlation between the Zonal Wind and the Zonal current at a depth of 60 m indicates that the fluctuations between the Zonal Wind and the zonal current depth of 60 m does not have a strong correlation with the largest coherence value that is 0.55 with a time leg 34 days. With fluctuation current at a depth of 60 m precedes wind fluctuation with a phase difference of 34 days. Keywords: coherence, phase difference, Ombai Strait

Sebaran Medan Massa dan Medan Tekanan di Perairan Barat Sumatera pada Bulan Maret 2001

Jurnal Fisika FLUX Vol 9, No 1 (2012): Jurnal Fisika Flux Edisi Februari 2012
Publisher : Lambung Mangkurat University Press

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Abstract

Penelitian tentang sebaran medan massa dan medan tekanan di perairan barat Sumatra dari data hasil survey oleh Baruna Jaya I pada Tanggal 21 Maret – 11 April 2001. Data parameter fisik air laut yang terdiri atas suhu, salinitas dan konduktivitas pada tiap interval kedalaman diperoleh dari hasil ekspedisi oseanografi. Analisi data dilakukan untuk menentukan Anomali Volume Spesifik (), Kedalaman Dinamik (Di) serta Kecepatan dan Arah Arus Relatif dan Absolut dari Arus Geostropik. Adapun untuk menghitung nilai-nilai tersebut ditentukan dengan dua metode yakni pertama melalui interpolasi linear (manual) dari data temperatur, salinitas dan densitas (t) tiap kedalaman pada tabel yang diberikan oleh Svedrup dan Bjerknes. Memperlihatkan kedalaman dinamik yang membentuk slop yang besar pada kedalaman kurang dari 100 meter sedangkan pada kedalaman berikutnya menunjukkan slop yang sangat kecil kecuali pada daerah dekat pantai dengan kedalaman berkisar antara 0 – 7,29 dyn.m. kecepatan arus relatif geostropik antar stasiun pada Transek 4 secara keseluruhan berkisar -6,43 – 4,11 m/s. Selain itu kecepatan arus geostropik cenderung ke arah tenggara dibandingkan kearah barat laut.

Pengukuran Frekuensi Alami Tanah dan Bangunan Akibat Gempabumi Dengan Menggunakan Alat Accelerometer di Kota Palu

Gravitasi Vol 15, No 2 (2016)
Publisher : Gravitasi

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Abstract

ABSTRAK Telah di lakukan penelitian untuk mengetahui nilai frekuensi alami tanah dan bangunan serta untuk mengetahui potensi terjadinya resonansi yang di alami oleh bangunan di Kota Palu, khususnya di bagian timur Sungai Palu. Pengukuran dilakukan terhadap mikrotremor menggunakan alat Accelerometer. Pengolahan data menggunakan program Geopsy dengan analisis HVSR (Horizontal To Vertical Spectral Ratio). Nilai rata-rata frekuensi alami bangunan mempunyai nilai frekuensi alami sekitar (1,1 – 3,1) Hz. Ada 70.59% bangunan yang sisanya berpotensi mengalami resonansi.Kata Kunci: Frekuensi, Mikrotremor, Accelerometer.

PENENTUAN CURRIE POINT DEPTH (CPD) PADA LAPANGAN PANASBUMI DAERAH BORA PROVINSI SULAWESI TENGAH MENGGUNAKAN DATA GEOMAGNET (MAGNETIK)

Gravitasi Vol 16, No 1 (2017)
Publisher : Gravitasi

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Abstract

ABSTRAK Penelitian untuk mengetahui sumber Currie Point Depth (CPD) lapisan bawah permukaan yakni kedalaman atas (Zt), kedalaman tengah (Zo) dan kedalaman basal (Zb) telah dilakukan di Lapangan PanasBumi Bora, Kabupaten Sigi Biromaru dengan menggunakan analisis spektrum data geomagnet. Tahapan dalam pengukuran anomali magnet adalah akuisisi data lapangan, koreksi IGRF dan koreksi variasi harian, dan pembuatan peta kontur anomali. Nilai anomali magnet tinggi (1700 nT) dan anomali magnet rendah (-200) diperoleh berdasarkan peta kontur anomali magnet. Teknik yang digunakan dalam peneliian ini adalah analisis spektrum untuk memperoleh kedalaman diperoleh dai sema lintasan untuk kedalaman atas, kedalaman tengah dan kedalaman basal adalah berturut-turut sebesar -1,15 km, -4,00 km dan 3,57 km. Kata Kunci : anomali magnetik, Analisis Spektrum, Currie Depth Point (CPD)

MAPPING OF TSUNAMI DISASTER RISK BASED SPATIAL IN PALU

Gravitasi Vol 14, No 2 (2015)
Publisher : Gravitasi

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Abstract

Mapping tsunami risk level has been carried out in the city of Palu in order to determine the areas at  a tsunami risk with a certain level. Tsunami risk is mapped by incorporating components of the tsunami threat, the physical, social vulnerability, economic vulnerability, environmental vulnerability then weighted using the Analytical Hierarchy Process (AHP) and subsequently processed using GIS software (Geographic Information System) in order to obtain spatial-based data. The percentage of tsunami risk areas is 1.4% (5 km2) of 366.89 km2 the total area of ​​Palu which distributed into six districts: District of Tawaeli of 25.47% (1.28 km2), District of Mantikulore 22.32% (1.12 km2), District of West Palu 18.95% (0.95 km2), District of North Palu 14.51% (0.73 km2), District of East Palu 12.22% (0.61 km2), and the District of Ulujadi 6.53% (0.33 km2). All those districts which potentially at risk tsunami are the districts directly adjacent to the Gulf of Palu. While the other two sub-districts: the District of Tatanga and District of South Palu located far from the beach so do not have exposure to the tsunami. Keywords:Tsunami, risk, vulnerability,spatial, AHP