Pengukuran di tiap titik dilakukan sebanyak 10 set dengan jumlah drop untuk setiap set sebanyak 120. Titik-titik yang akan dijadikan pembahasan dalam makalah ini adalah GBU018 di Jakarta dan GBU035 di Makassar. Tujuan penulisan makalah ini adalah memaparkan teknik pengukuran dan pengolahan data gayaberat absolut di GBU yang merupakan bagian dari Jaring Kontrol Gayaberat (JKG) dengan menggunakan gravimeter A-10. Pada tahun 2017, Badan Informasi Geospasial (BIG) melakukan pengukuran gayaberat absolut di beberapa pilar Gayaberat Utama (GBU) di Indonesia dengan menggunakan gravimeter A-10. Pengukuran gayaberat absolut merupakan pengukuran nilai gayaberat dengan mengamati percepatan vertikal benda jatuh bebas.

PositiveĪnomaly responses indicate there are Groundwater surface increase with the biggest increase is recorded inĬentral Jakarta which reaches 10,4 m caused by seawater intrusion during observations Responses were obtained in Central and West Jakarta as much as 130,67 μGal and 51,31 μGal. Those decreases are caused by massive groundwater exploitation. Groundwater surface decreases in those places with South Jakarta has the biggest decrease which measured asīig as 13,4 m. Negative anomaly responses show that there are Responses as much as -53,98 μGal and -168,57 μGal. Based on analysis, North and South Jakarta give negative anomaly In this research, observation was done 3 times with time window chosen is 1 month startįormMarch 30th to June 8th 2017.

It is done by reobserving gravity in a point on the earth surface with a given time Timelapse microgravity method is used in pupose to learn Represent Central, North, West, and South Jakarta. The analysis of the height changes versus the gravity changes suggested that the subsidence was caused by soil compaction and/or groundwater level changes, which are likely connected with excessive groundwater extraction.Ī research has been conducted to learn about groundwater dynamics in Jakarta by observing 5 points that Nevertheless, the observed gravity changes along the northern coastal area of Jakarta showed an increase in gravity, which was consistent with the GPS results. For these reasons, the number of reliable gravity data was restricted. Moreover, some of the gravity points were lost mainly due to construction work.

The A10 measurements, particularly those conducted before 2010, were adversely affected by the influence of the high-temperature and high-humidity climate, which caused problems with the ion vacuum pump, laser controls and unstable behavior of the data processing personal computer. To investigate the cause of land subsidence occurring in Jakarta, Indonesia, we have conducted absolute gravity measurements near or at the existing GPS points in 2008, 2009, 2010, 20, by using a portable absolute gravimeter Micro-G LaCoste A10 serial number 017 (MGL A10-017).

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