Thermal Regime of the Aegean Area
Document Actions
The temperature field is considered to be stationary. The thermal parameters used for the computation are given in table 1. The computed thermal field is given in Fig. 2, and the temperature distribution was calculated at the Moho discontinuity taken from Fig. 1 and also at a depth of 60 km.
Both temperature curves show that the thermal field at the Sea south of Crete has low values which do not exceed 300o C at a depth of 60 km. To the north of Crete, and particularly in the zone of the volcanic arc along Santorini, the temperatures increase drastically, exceeding 1000o C at the same depth. A further high temperature zone is located at the Saros Trench of the north Aegean Sea, where very high heat-flow values have been recorded.
The Aegean Sea is characterized by high heat-flow and high temperature values, compared to the thermal distribution of the surrounding seas. The high temperature values might be explained by one of the three different tectonic hypotheses existing for the development of the Aegean arc:
- either by an ascending lithothermal system which causes the creation of a crustal dome, crustal thinning and a south-east extension of the Aegean Sea (Makris 1977);
- or by a lithothermal system that developed below the Aegean Sea due to the subduction of the Tethean Ocean below the alpine zone (Berkhemer 1976; Biju-Duval et al. 1976);
- or due to the mechanical extension of the Aegean area (Brunn et al. 1976) and temperature increase as a consequence (McKenzie 1978) of this mechanical process.
Table 1: Parameters of the computation of two-dimensional models of the Aegean area
| 1. | Number of layers: | 4 |
| 2. | Sufrace temperature: | To = 10o C |
| 3. | Heat production in HGU units: | A (1) = 1.5 . 10-13 A (2) = 6.4 . 10-13 A (3) = 0.6 . 10-13 A (4) = 0.2. 10-13 |
| 4. | Thermal conductivity K in cal/cm sec o C: | K (1) = 2.5 . 10-3 K (2) = 6.5 . 10-3 K (3) = 5.0 . 10-3 K (4) = 10.0 . 10-3 |
------------------------------------
| For figures and table please refer to book. | |
| Figures and table mentioned in this paper: | |
| Fig. 1: | 2-D crustal model along the line Cyrenaica-Bulgaria obtained from gravity data constrained by seismic observations. The model shows that the calculated gravity model anomaly (Bouquer) can only be adjusted to the observed one if a low density upper mantle is introduced below the Aegean Sea and the Mediterranean Ridge. |
| Fig. 2: | A two-dimentional thermal model computed according to the crustal structure of Fig. 1 and the thermal parameters as given in table 1. The heat-flow distribution of the Aegean area is given at the upper part of the drawing. HF-Curve 1, at the lower part of the drawing, gives the temperature distribution in oC at the Moho discontinuity. Curve 2 presents the temperature distribution at 60 km depth. |
| Table 1: | Parameters of the computation of two-dimensional models of the Aegean area. (This table can be found in text above). |
------------------------------------
| Source: | "Thera and the Aegean World II" |
| Papers and Proceedings of the Second International Scientific Congress, Santorini, Greece, August 1978. | |
| Pages: | pp. 45 - 48 |
| Written by: | - J. Makris - C. Stobbe |
| Institute of Geophysics, University of Hamburg, Germany | |
| Book information: | |
| ©Thera and the Aegean World | |
| ISBN: | 0 9506133 2 0 |
| Published by: | Thera and the Aegean World, 105-109 Bishopsgate, London EC2M 3UQ |
| Editor: | C. Doumas |
| To order the book from amazon.co.uk: | http://www.amazon.co.uk/exec/obidos/ASIN/0950613320/qid=1142346164/sr=1-4/ref=sr_1_0_4/026-5808754-1144459 |