Τίτλος:
Gravity observations on Santorini island (Greece): Historical and recent
campaigns
Γλώσσες Τεκμηρίου:
Αγγλικά
Περίληψη:
Santorini is located in the central part of the Hellenic Volcanic Arc
(South Aegean Sea) and is well known for the Late-Bronze-Age
“Minoan” eruption that may have been responsible for the decline of
the great Minoan civilization on the island of Crete. To use gravity to
probe the internal structure of the volcano and to determine whether
there are temporal variations in gravity due to near surface changes, we
construct two gravity maps. Dionysos Satellite Observatory (DSO) of the
National Technical University of Athens (NTUA) carried out terrestrial
gravity measurements in December 2012 and in September 2014 at selected
locations on Thera, Nea Kameni, Palea Kameni, Therasia, Aspronisi and
Christiana islands. Absolute gravity values were calculated using raw
gravity data at every station for all datasets. The results were
compared with gravity measurements performed in July 1976 by DSO/NTUA
and absolute gravity values derived from the Hellenic Military
Geographical Service (HMGS) and other sources. Marine gravity data that
were collected during the PROTEUS project in November and December 2015
fill between the land gravity datasets. An appropriate Digital Elevation
Model (DEM) with topographic and bathymetric data was also produced.
Finally, based on the two combined datasets (one for 2012-2014 and one
for the 1970s), Free air and complete Bouguer gravity anomaly maps were
produced following the appropriate data corrections and reductions. The
pattern of complete Bouguer gravity anomaly maps was consistent with
seismological results within the caldera. Finally from the comparison of
the measurements made at the same place, we found that, within the
caldera, the inner process of the volcano is ongoing both before, and
after, the unrest period of 2011-2012.
Συγγραφείς:
Paraskevas, Melissinos
Paradissis, Demitris
Raptakis,
Konstantinos
Nomikou, Paraskevi
Hooft, Emilie
Bejelou,
Konstantina
Περιοδικό:
Contributions to Geophysics and Geodesy
Εκδότης:
SLOVAK ACAD SCIENCES, EARTH SCIENCE INST
Λέξεις-κλειδιά:
Santorini; gravity; Bouguer; Free Air Anomaly; HMGS
DOI:
10.31577/congeo.2021.51.1.1
