Vertical deflection can be determined by geometrical and physical measurement. In geometrical way, vertical deflection is obtained by comparing astronomical coordinate and geodetical coordinate. In physical way, vertical deflection can be computed from gravity measurement. In the past, vertical deflection was computed from gravity anomaly data. Gravity anomaly data measurement is difficult because it need reduction of gravity from surface of the earth to the geoid using orthometric height from spirit level measurement. In modern era, gravity anomaly data may be replaced by gravity disturbance data whose only required gravity and GNSS (Global Navigation Satellite System) measurement. This research aims to determine vertical deflection in Semarang City from terrestrial gravity disturbance data. The gravity data were measured in March of 2016. Formula of Vening Meinesz that usually used for vertical deflection was replaced by new formula that generated from derivation of function of Hotine. Applying gravity disturbance gave vertical deflection of east-west component that were vary from -1.2” to 12.2” while north-south component were vary from -4.2” to 4.2”. Comparing vertical deflection as computed from terrestrial data to as computed from EGM2008 coefficients showed conformity in shape and values. It was concluded that derivation of function of Hotine could be applied for vertical deflection determination from gravity disturbance.

Jatirunggo geothermal field is a hot spring manifestation with temperatures ranges 35°C-38°C. Previous research by the resistivity method concluded that the Jatirunggo field as an outflow zone of a geothermal system. This study aim is demonstrating the possibility of the permeable geothermal zone detection by using seismic refraction method’s a complement of the geothermal conceptual model — the main research method by conducting refraction seismic. The method mainly applying active seismic wave to the media and identify the velocity properties of the pathway as a recording logger used 2D geode module which is consisting of 8 channels geophone by 5 meters geophone interval. The penetrating depth can reach 15 m - 20 m. Processing of velocity model has been used Hagiwara algorithm of 2 layers. The result shows velocity seismic recorded has a range of 138 m/s of topsoil layer up to 1742 m/s on the second layer. Based on the velocity model we can interpret the existence of a fault structure corresponding to the emergence of the hot springs, but the method was impenetrable up to the structured target.

Telah dilakukan penelitian tentang analisis karakteristik sumur bor. Penelitian ini merupakan suatu contoh penelitian tentang analisis karakteristik sumur bor di daerah batu karang dan tandus. Penelitian mengambil contoh di sumur RSPTN Universitas Udayana berlokasi di Jimbaran Badung Bali. Analisis yang dilakukan efisiensi sumur (Ew), faktor pengembangan sumur (Fd), perbaikan sumur (C) dan debit optimum (Q_opt). Hasil penelitian didapatkan bahwa berdasarkan hasil pengukuran geolistrik, pada sumur bor memang ada akuifer. Sumur yang dibikin termasuk sumur yang efesien dengan tingkat efisiensi   84,71%. Ini berarti sangat efesien untuk pengambilan air. Sumur memiliki faktor pengembang 0,077864 hari/m³ Ini berarti sumur sangat baik untuk dikembangkan. Nilai C = 28994,2. Ini berarti apabila sumurnya ada kendala misalnya debitnya mengecil, maka sumur sulit dikembalikan menjadi seperti semula. Kapasitas jenis (Sc) rata-rata didapat: 0,0196908 m²/s, nilai ini lebih besar dari 0,005.  Ini berarti sumur memiliki produktifitas tinggi. Debit optimum (Q_opt) = 0,00782 m³/s = 28,152 m³/jam. Drowdown optimum (Sw_opt) = 2,17 m. Nampak bahwa adanya keterbatasan kuantitas cadangan air. Uji sumur dengan debit konstan (0,00328 m³/s) telah dilakukan selama 7,5 jam ini berarti air sumur telah diambil 88,56 m³, tetapi sumur hanya mengalami penurunan permukaan air sebesar 22,2 cm secara konstan.

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The SDP geothermal research area geographically located in eastern Indonesia where there are geothermal manifestations of hot springs. 3D modeling and vertical-horizontal gradient analysis are used to determine the presence of subsurface structures of the study area. Separation of complete Bouguer anomaly data to obtain regional and residual anomalies has been done by upward continuation. The results of the horizontal and vertical gradients indicate that the presence of the geothermal manifestation of MAP 1 hot spring is controlled by the presence of trending northwest-to-southeast fault. We interpret the emergence of manifestations due to the presence of a permeable zone in the form of the fault structure. 3D modeling shows the existence of alluvium sediment, sedimentary rocks, limestones, ultrabasas (peridotite), granite, metagranite, gneiss and the presence of trending northwest trending to the southeast fault.