Time dependent microgravity data analysis of the 30th October 2020 Samos earthquake

The subduction of the Eastern Mediterranean oceanic plate under the Aegean microplate and the

westward movement of the Anatolian microplate along the North Anatolian Fault Zone provides the

formation of regional deformation. The region of the Northern Samos Fault, which is the source of the

30 October 2020 Samos Earthquake (Mw=6.9), corresponds to a highly deformed back-arc area in the

middle-eastern part of the Aegean microplate. The main shock of the 30th October 2020 Samos

earthquake was connected to Izmir average 70 km away. After the Samos Earthquake, structural

damage occurred in the buildings in Bornova and Bayrakli districts of Izmir such as total collapse (17

buildings), severe damage, moderate damage and mild damage. During this time, about 115 people

died. In more than one week, close to five thousand aftershocks occurred, within this scope, time

depending microgravity data were measured. The microgravity method is affected directly by density

distribution under the surface and especially the mass changes to the surrounding environment. The time-dependent microgravity data show the vertical movements of the masses in the measurement time

scale. In this study, vertical mass changes belonging to time-dependent microgravity data of around

the Izmir (Turkey) were presented in the years 2009, 2010, 2011 (Project no TUBITAK 108Y285) and

2020 (TUBITAK Earthquake Focused Earth Sciences Research Area Fieldwork), at the same stations.

The microgravity data in 2020 were measured right after 30th October 2020 Samos earthquake. In the

time-dependent microgravity studies were carried out at 7 stations in Izmir, where 30th October 2020

Samos earthquake destruction damage was high. After that, using GravProcess software, the data

were analyzed with the help of the network solution. As a result, network results, the drift corrections,

Free air gravity values, Bouguer gravity values, Gravity field values and pressure effect values were

obtained.

As a result, it was examined together with the time-dependent microgravity measured in the years

2009-2010-2011-2020. Possible earthquake effects on microgravity values before and after the 30

October 2020 Samos Earthquake were evaluated.