Earthquake Monitoring Using Variometric GPS Data Processing

. Variometric Approach for Standalone Engine Displacement Analysis (VADASE) is a technique used in seismology purposes using GPS measurements. VADASE is used to determine the small displacement from the earthquake. The VADASE L1 solution is using the klobuchar ionospheric model. In this study VADASE was used in earthquakes with magnitudes> 7 to> 9 righter scales. In the scale of the earthquake category> 9 used Indian Ocean earthquake of December 26, 2016 with the strength of 9.1 SR by using the closest SAMP station and the Japanese Tohoku earthquake of March 11, 2011 with a power of 9.1 SR using 4 different stations namely MIZU, KMSV, TSK2 and Knii . The earthquake category with a scale of> 8 SR is the offshore earthquake Bio Bio, Chile on February 27, 2010 with a power of 8.8 SR using 2 stations namely ANTC and SANT, the Bengkulu Indonesia earthquake on 12 September 2007 with a power of 8.4 SR using the SAMP station, an illaper earthquake, chile September 16 2015 with 8.3 SR using SANT station, and Tres Piscos earthquake - Mexico on September 8, 2017 with a power of 8.2 SR using IENG station. Earthquake with a strength of> 7 SR, namely the amberlay-New Zealand earthquake on November 13, 2016 with a strength of 7.8 SR using MRLL and WGTN stations, Puerto quello-chile earthquake on December 25, 2016 with a strength of 7.6 SR using COYQ station, Java sea earthquake -Indonesia on 8 August 2007 with 7.5 SR power using BAKO station and ayula mexico earthquake on 19 september 2017 with 7.1 SR power using INEG station. From the results of VADASE, the farthest distance from the epicenter to the observation station is 1100 km (INEG station) and the closest distance is 95 km (BAKO station). The highest speed is 0.12 m / s after 5 minutes from the earthquake in the earthquake Offshore Bio Bio-Chile 2010 uses the SANT station and the lowest speed is 0.006 m / s after 10 minutes from the earthquake in the 2007 Bengkulu earthquake using the SAMP station. Whereas in the other earthquakes was the 2011 Tohoku earthquake with a speed of 0.06 m / s after 1 minute using MIZU station, the amberley-New Zealand earthquake 2016 with a speed of 0.015 m / s after 1 minute using the MRLI satellite, Puerto quello- earthquake Chile 2016 with a speed of 0.025 m / s after 40 minutes using the COYQ satellite.


Preface
Variometrric Approach for Standalone Engine Displacement Analysis (VADASE) is a technique used in seismology purposes using GPS measurements. VADASE is used to determine the small displacement of the earthquake. The VADASE L1 solution is using the klobucha is proposed VADASE r ionospheric model. because it is an innovative strategy in GNSS data processing that uses the VADASE algorithm. VADASE is able to estimate in real time the speed and displacement in a global reference frame (ITRF), using introductory phase observation and high-speed broadcast products (1 Hz or more) (orbit, clock) collected by stand-alone GNSS receivers, achieving transfer accuracy in 1 -2 cm (usually better) for intervals of up to several minutes. VADASE can be used in real time even on the GNSS receiver board. VADASE can display time and waveform changes caused by earthquakes with accuracy can only be achieved with seismometers or with other 2 GNSS approaches such as Precise Point Positionong (PPP) and Differential Positioning (DP). In this study VADASE is used to monitor changes in velocity after an earthquake which is divided into several categories based on earthquake magnitude, namely strength> 9 SR, earthquake strength> 8 SR, and earthquake strength> 7 SR. By removing the nearest GPS station to the earthquake it can be used to determine the velocity of each earthquake to the nearest station. For earthquake category with magnitude> 9 SR using the Indian / Aceh oceanic earthquake in 2004 using the SAMP station, the Japanese Tohoku earthquake in 2011 using MIZU, KMSV, TSK2 and KGNI stations. For the earthquake category with magnitude> 8 SR, using Chile's Bio Bio earthquake in 2010 using ANTC station and SANT station, for the Bengkulu-Indonesia earthquake in 2007 using the SAMP station, for the 2015 Illapel-Chile earthquake using the SANT station, the Tres Picos earthquake -Mexico in 2017 using IENG station. Earthquake with a strength of> 7 SR using the Amberley earthquake. Vadase is used to determine the speed of displacement of x, y and z at the time of the earthquake. The Indian Ocean earthquake struck in 26 December 2016 at 00:58:53 UTC, The quake which had the power of 9.1 SR was centered on 3,295°N -95,982°E.
By using samp station data, the following velocity values are generated: In the case of the Tobuk earthquake, the GPS data used came from observations of 4 different stations. The GPS station used is:  Station mizu, with distance from the epicenter ±142 km  Station kmsv, with distance from the epicenter ±300 km  Station tsk2, with distance from the epicenter ±310 km  Station kgni, with distance from the epicenter ±385 km The following are the results of variometric processing in the 2011 Tobok earthquake:  On the Ksmv station data at 5:50 p.m. to 8:58 p.m. is not available. So at that hour the resulting variometric value is equal to 0. In the case of the above earthquake, the GPS data used came from observations of 2 different stations. The GPS station used is: • Station antc, distance from the epicenter ±180 km • Station sant, distance from the epicenter ±380 km Here are the results of variometric processing in the 2010 Chile earthquake: a) Station antc (distance from the epicenter ±180 km) Fig. 11. Results of the value of the velocity of the antc station at 5.5 UTC -7.5 UTC

Earthquake Bengkulu -Indonesia 2007 (8,4 SR
Bengkulu Earthquake on 12 September 2007 at 11:10:26 UTC, the earthquake which has a power of 8.4 SR was centered at 4.438 ° S -101.336 ° E with a depth of 34 Km.
By using samp station data, the following velocity values are generated:
By using sant station data, the velocity value is generated:
By using ieng station data, the following velocity values are generated:

Earthquake Amberley -New Zealand 2016 (7,8 SR)
The earthquake in Amberley, New Zealand occurred on November 13, 2016 at 11:02:56 UTC. The earthquake centered on 42.737 ° S -173.054 ° E with a depth of 15.1 km has a power of 7.8 SR.
In the case of the above earthquake, the GPS data used came from observations of 2 different stations. The GPS station used is:  Station mrl1, distance from the epicenter ±140 km  Station wgnt, distance from the epicenter ±210 km Here are the results of variometric processing in the 2016 New Zealand earthquake: a) Station mrl1 (distance from the epicenter ±140 km)  By using coyq station data, the following velocity values are generated : By using the bako station data, the following velocity values are generated:
By using the ineg station data, the following velocity values are generated: