176
since 1961
BALTICA Volume 36 Number 2 December 2023: 176–189
https://doi.org/10.5200/baltica.2023.2.7
Correlations between seismic b-value and heat flow density in Vlora-Lushnja-Elbasani-Dibra
Fault Zone in Elbasani area, central Albania
Rrapo Ormeni
*
, Albana Hasimi, Serkan Öztürk, Ervin Çomo
Ormeni, R., Hasimi, A., Öztürk, S., Como, E. 2023. Correlations between seismic b-value and heat flow density in
Vlora-Lushnja-Elbasani-Dibra Fault Zone in Elbasani area, central Albania. Baltica, 36 (2), 176–189. Vilnius. ISSN
0067-3064.
Manuscript submitted 20 September 2023 / Accepted 30 November 2023 / Available online 14 December 2023
© Baltica 2023
Abstract. In this study, the correlations between the heat flow density and seismotectonic b-value in the El-
basani area of Albania were investigated to understand the how low-velocity layers underneath the Elbasani
area in central Albania struggling the large-scale Vlora-Lushnja-Elbasani-Dibra Fault Zone affect the heat flow
data. For this purpose, the heat flow and regional distribution of b-value were imaged for different locations
and depths. To achieve the analysis, the Albanian Seismological Catalogue for the period between 1 July 1968
and 26 December 2022, including 1830 earthquakes with a local magnitude of 0.5 ≤ M
l
≤ 5.2 that occurred at
the depths below 70 kilometres, was considered. The b-value was calculated as 1.03 ± 0.06 by considering
the magnitude of the completeness value as Mc-value = 2.6. This result shows that the b-value of earthquake
distribution in the Vlora-Lushnja-Elbasani-Dibra (VLED) fault zone is well represented by the Gutenberg
and Richter (G-R) scaling law with the b-value close to 1.0. The regional variations of the b-value show that
b-values smaller than 0.9 were observed in the western and south-western parts of the Llinxha-Kozan thermal
water belt. The depth distribution of the b-value indicates that there exists a sharp decrease in the b-values
from 1.15 to 0.7 in the depths varying from 5 to 20 km. The highest heat flow values were observed on the
Dumrea diapiric dome and in the central part of the Elbasani area. Thus, our analysis indicates significant and
robust correlations between the geothermal and earthquake distribution. The discontinuity of Moho interface
is deep in the regions where high b-values were observed. Low b-values are found at the depths ranging from
20–25 km and 35–40 km in the Dumrea evaporite massif area. We have evidence that high b-values and large
heat flow values are related to the low seismic velocity layers underneath the Elbasani area. The low-velocity
zone (LVZ) in Albania occurs in the Earth’s crust and in the upper mantle. It is characterized by an unusu-
ally low seismic shear wave velocity compared to the surrounding depth intervals. It is well known that the
low-velocity layers in the Elbasani area are determined in the upper crust, at shallow depths of 2–4 km, and in
the middle crust at a 10–14 km depth. Hence, it is suggested that the Moho interface in the eastern part of the
Elbasani area is relatively deep (45 km) compared to the western part of Albania (35 km), and the magnitude
of earthquakes is smaller where the high heat flow values were observed.
Keywords: VLED fault zone; geothermal; earthquakes; Moho; low-velocity zone; tectonics; b-value
Rrapo Ormeni* (rrapo55@yahoo.com), https://orcid.org/0000-0002-5514-2204\
Albana Hasimi (albahasimi@gmail.com), https://orcid.org/0009-0005-9604-9707\
Ervin Çomo (elvincomo1@gmail.com), https://orcid.org/0009-0001-6444-7448\
Institute of Geosciences, Polytechnic University of Tirana, Don Bosko str.60, Tirana, Albania
Serkan Öztürk (serkanozturk@gumushane.edu.tr), https://orcid.org/0000-0003-1322-5164
\
Department of Geophysics, Gümüşhane University, 29100, Gümüşhane, Turkey
*Corresponding author