| More

DGPS AND MAGNETOTELLURIC CONSTRAINTS ON THE CONTEMPORARY TECTONICS OF THE SANTORINI VOLCANIC COMPLEX, GREECE

Views: 453 Downloads: 322
E. Papageorgiou, A. Tzanis, P. Sotiropoulos, Ε. Lagios
E. Papageorgiou, A. Tzanis, P. Sotiropoulos, Ε. Lagios

Abstract


The study of vertical and horizontal crustal movements at the Santorini Volcanic Complex (SVC), as deduced by Differential GPS measurements revealed that an intricate pattern of five distinct domains with different horizontal kinematics: The West SVC (Akrotiri peninsula and Therassia) with very significant NNW-ward motion, North Thera with rather significant NW-ward motion, East Thera (Monolithos), with significant SE-ward motion, South Thera with significant NW-ward motion and, finally, central Thera with small westward motion. An apparently dextral, NNW-SSE oblique-to-strike-slip fault emerges as a prominent tectonic structure, separating the West SVC from the rest of the complex; this is the “Santorini Fault Zone”. Additional insight is afforded by the results of MT and GDS surveys: a significant NNW-SSE conductive zone was detected, which is collocated with the purported NNW-SSE fault zone indicated by DGPS analysis and may be explained as an epiphenomenal conductivity anomaly. The observed deformation pattern enables the drafting of a qualitative model of contemporary tectonics, which is also presented and discussed. The model is plausible but certainly incomplete and pending verification with numerical modelling and additional observations

Keywords


Santorini; Differential GPS; Magnetotellurics; tectonic deformation;

Full Text:

PDF

References


Altamini, Z., Sillard, P. and Boucher, C., 2002. ITRF2000: A new release of the International Terrestrial Reference

Frame for Earth Science applications. J. Geophys. Res., 107(B10), 2214, doi:10.1029/2001JB000561.

Bohnhoff, M., Rische, M., Meier, Th., Becker, D., Stavrakakis, G. and Harjes, H-P., 2006. Microseismic

activity in the Hellenic Volcanic Arc, Greece, with emphasis on the seismotectonic setting of the Santorini-Amorgos

zone. Tectonophysics, 423, 17-33.

Delibasis, N., Chailas, S. and Lagios, E., 1989. Surveillance of Thera Volcano-Microseismicity Monitoring.

Proc. 3rd Intern. Congress “Thera and the Aegean World”, 2, Sept. 3-9, Santorini, Greece,

-206.

Drakopoulos, J., Makropoulos, C., Stavrakakis, G., Panagiotopoulos, D., Papanastasiou, D., Hatzidimitriou,

P., Papazachos, C., Vargemezis, G. and Savvaidis, A., 1996. Seismic monitoring of Santorini

Volcano: Seismological network and processing of the seismological data. Santorini Volc. Lab., II, 15.

Druitt, T.H., Mellors, R.A., Pyle, D.M. and Sparks, R.S.J., 1989. Explosive volcanism on Santorini,

Greece. Geological Magazine, 126, p. 95–126.

Druitt, T.H., Edwards, L., Mellors, R.M., Pyle, D.M., Sparks, R.S.J., Lanphere, M., Davies, M. and Barreiro,

B., 1999. Geological Map of the Santorini Islands, 1:20000. Geological Society of London,

Memoir, 19, 178p.

Dvorak, J.J. and Dzurisin, D., 1997. Volcano geodesy; the search for magma reservoirs and the formation

of eruptive event. Rev. Geophys., 35, 343–384.

Egbert, G.D. and Booker, J.R., 1986. Robust estimation of geomagnetic transfer functions. Geophys. J.

R. astr. Soc., 87, 173-194.

Farmer, G.F, Newman, A.V., Psimoulis, P., Stiros, S., 2007. Geodetic Characterization of Santorini Caldera

from Continuous GPS Measurements. EOS.

Fernández, J., Carrasco, J.M., Rundle, J.B. and Arána, V., 1999. Geodetic methods for detecting volcanic

unrest: A theoretical approach. Bull. Volcanol., 60, 534–544.

Ferrara, G., Fytikas, M., Guiliano, O. and Marinelli, G., 1980. Age of the formation of the Aegean active

volcanic arc. In: Doumas C. (ed). Thera and the Aegean World II, 37-41.

Fouqué, F., 1879. Santorin et ses eruptions. Masson et Cie., Paris, 440p.

Heiken, G. and McCoy, F., 1984. Caldera development during the Minoan eruption, Thera, Cyclades,

XLIII, No 1 – 355

Greece. J. Geophys. Res., 89, 8441-8462.

I.G.M.E., 1995. Surficial sediment map of the bottom of the Aegean Sea, Scale 1:200,000: Santorini

sheet, IGME, Athens, Greece.

Jackson, J.A., 1994. Active tectonics of the Aegean region. Annual Reviews of Earth and Planetary Sciences,

, 239-271.

Lagios, E., Galanopoulos, D., Sotiropoulos, P. and Vougioukalakis, G., 1996. Audio-Magnetotelluric

study of Thera Volcano. Santorini Volc. Lab., II, 10.

Mountrakis, D., Pavlides, S., Chatzipetros, A., Meletidis, S., Tranos, M., Vougioukalakis, G. and Kilias,

A., 1998. Active deformation in Santorini. In: Casale R., Fytikas M., Sigvaldarsson G. & Vougioukalakis

G. (eds). The European laboratory volcanoes. European Commission, EUR 18161, 13-22.

Papageorgiou, E., Lagios, E., Vassilopoulou, S. and Sakkas, V., 2007. Vertical & Horizontal Ground Deformation

of Santorini Island deduced by DGPS measurements. Proceedings of the 11th International

Conference Geol. Soc. Greece, Athens, Greece. Bull. Geol. Soc. Greece, 40, 1219-1225.

Pe-Piper, G. and Piper, D.J.W., 2005. The South Aegean active volcanic arc: relationships between magmatism

and tectonics. Develop. in Volc., 7, 113-133.

Perissoratis, C., 1995. The Santorini volcanic complex and its relation to the stratigraphy and structure

of the Aegean Arc, Greece. Marine Geology, 128, 37-58.

Pichler, H. and Kussmaul, S., 1980. Comments on the geological map of the Santorini Islands. In:

Doumas, C. (ed.). Thera and the Aegean World II. The Thera Foundation, London, 413-427.

Pichler, H., Guenther, D. and Kussmaul, S., 1980. The Geological Map of Greece. Thira Island, Inst. Geol

Min. Exploration, Athens 1980.

Reck, H., 1936. Santorini. –Der Werdergang eines Inselvulcans und sein Ausbruch 1925-1928. Dietrich

Reimer, Berlin, 3 vols. MANCA.

Rodi, W. and Mackie, R.L., 2001. Nonlinear conjugate gradients algorithm for 2-D magnetotelluric inversion,

Geophysics, 66, 174–187.

Rokityansky, I.I., 1982. Geoelectromagnetic investigations of the Earth’s Crust and Mantle. Springer Verlag.

Stiros, S. and Chasapis, A., 2003. Geodetic monitoring of the Santorini (Thera) volcano. Survey Review,

, 287, 84-88.

Stiros, S., Chasapis, A. and Kontogianni, V., 2003. Geodetic evidence for slow inflation of the Santorini

Caldera. Proceedings, 11th FIG Symposium on Deformation Measurements, Santorini, Greece.

Tzanis, A. and Beamish, D., 1989. A high resolution spectral study of audiomagnetotelluric data and noise

interactions. Geophys. J., 97, 557-572.

Yee, E. and Paulson, K.V., 1987. The Canonical decomposition and its relationship to other forms of magnetotelluric

impedance tensor analysis. J. Geophys., 61, 173–189.


Refbacks

  • There are currently no refbacks.


Copyright (c) 2017 E. Papageorgiou, A. Tzanis, P. Sotiropoulos, Ε. Lagios

Creative Commons License
This work is licensed under a Creative Commons Attribution-NonCommercial 4.0 International License.