Investigating the tectonic subsidence on Java Island using GNSS GPS campaign and continuous

Many places around Java island are experiencing land subsidence with the rates vary from few centimeter to order of tens centimeter per year. Question arises on what would be the causes of the subsidence in the area. The tectonic is one of the suspected causes along with anthropogenic causes (e.g. ground water overexploitation). The question is very important for proper and effective mitigation or adaptation. As we can see the impact from subsidence like damaging on infrastructures, wider area expansion of flood, etc. indeed they are formed a quite serious disaster now. If the tectonic play significant role, in this case the adaptation is more effective than mitigation, etc. GNSS GPS technology is a passive, all-weather satellite-based navigation and positioning system, which is designed to provide precise three dimensional positions and velocity, as well as time information on a continuous worldwide basis. In the context of subsidence as we highlight above, GPS could provide very accurate level (millimeter level) to determine the subsidence signal if existed. This paper will highligt the investigation of tectonic subsidence over Java island by using data measurements from GNSS campaign and continue. Our preliminary result shows no tectonic subsidence over Java island.