Estimation of Curie point depths and heat flow from Ardebil province, Iran, using aeromagnetic data

Abstract

This study attempts to estimate the Curie point depth (CPD) using the centroid and forward modelling of the spectral peak methods in the Sabalan geothermal field in Ardabil, NW of Iran. The reduced-to-pole aeromagnetic data were divided into 18 overlapping blocks of the sizes of 100 × 100 km. In the centroid method, the average depth to the top of the deepest crustal block, Z t , was first computed by linear fitting to the second longest wavelength segment of the power spectrum of aeromagnetic data. Then, depth to the centroid of the deepest crustal block, Z 0 , was computed by linear fitting to the longest wavelength segment of the power spectrum of the aeromagnetic data. The depth to the magnetic bottom was obtained from Z b = 2Z 0 − Z t . In the forward modelling of the spectral peak method, the modelled spectra fitted to the observed spectrum iteratively and Z t and Z b were finally estimated. According to the obtained results, the CPD varies from 10 to 18.6 km. The Curie temperature of magnetite was used to determine the thermal gradient and the heat flow in the area. The study area is found to have a great energy potential in the west, northwest and the southwest of the Sabalan with shallow CPD, high geothermal gradient and heat flow.

Tectonic and structural characteristics of Erzurum and its surroundings (Eastern Turkey): A detailed comparison between different geophysical parameters

“…CPD values range from 11.73 to 19.8 (Table 2, Figure 18). Shallow CPD values may be associated with thin crust, geothermal potential and young volcanism (Aydın and Oksum, 2010; Khojamli et al, 2016). The largest CPD values were obtained in the centre of Erzurum and its north.…”

Estimation of Curie Point Depth (CPD) across the Pan African Belt in Northern Cameroon from Aeromagnetic Data

“…The 2D radial power spectrum (Figure 4(c)) of the upward continued RTE data for each window was then computed. Next, the long wavelengths of regional magnetic anomalies were removed using a first-order polynomial trend surface for each block, and the grids were expanded by 10% to lessen the edge effects of using the Fourier Transform in determining the power spectrum [45].…”

Curie Point Depth, Geothermal Gradient and Heat-Flow Estimation and Geothermal Anomaly Exploration from Integrated Analysis of Aeromagnetic and Gravity Data on the Sabalan Area, NW Iran

“…But for the bodies that have bases deeper than length/2p, they may not be appropriately resolved by spectral method . Thus, based on the results of previous studies on this region (Amirpour-asl 2010; Khojamli et al 2016), the study area was divided into 100 9 100 km subregions data.…”

“…For this purpose, the bottom depth of a magnetic source from aeromagnetic data is considered to be the Curie point depth. The CPD estimation from magnetic data has been widely used to determine the thermal structure of the crust in various tectonic settings (Smith et al 1977;Connard et al 1983;Okubo et al 1985;Blakely 1988;Tanaka et al 1999;Dolmaz et al 2005;Ross et al 2006;Maden 2010;Aboud et al 2011;Rao et al 2011;Bansal et al 2013;Hsieh et al 2014;Obande et al 2014;Starostenko et al 2014;Nwankwo and Shehu 2015;Saibi et al 2015;Khojamli et al 2016;Bilim et al 2016). Amirpourasl et al (2010) produced a CPD map of whole Iran.…”