Numerical investigations of fault-induced seawater circulation in the Seferihisar-Balcova Geothermal system, western Turkey


Magri F., AKAR A. T., GEMİCİ Ü., Pekdeger A.

HYDROGEOLOGY JOURNAL, cilt.20, sa.1, ss.103-118, 2012 (SCI-Expanded) identifier identifier

  • Yayın Türü: Makale / Tam Makale
  • Cilt numarası: 20 Sayı: 1
  • Basım Tarihi: 2012
  • Doi Numarası: 10.1007/s10040-011-0797-z
  • Dergi Adı: HYDROGEOLOGY JOURNAL
  • Derginin Tarandığı İndeksler: Science Citation Index Expanded (SCI-EXPANDED), Scopus
  • Sayfa Sayıları: ss.103-118
  • Anahtar Kelimeler: Numerical modeling, Thermal conditions, Fault, Seawater intrusion, Turkey, COUPLED GROUNDWATER-FLOW, FLUID-FLOW, PERMEABILITY STRUCTURE, NEOTECTONIC STRUCTURES, CARBONATE PLATFORMS, REFLUX CIRCULATION, SEDIMENTARY BASINS, SOLUTE TRANSPORT, HEAT-TRANSFER, CONVECTION
  • Dokuz Eylül Üniversitesi Adresli: Evet

Özet

The Seferihisar-Bal double dagger ova Geothermal system (SBG), Turkey, is characterized by temperature and hydrochemical anomalies along the faults: thermal waters in northern Bal double dagger ova are heated meteoric freshwater, whereas the hot springs of the southern Seferihisar region have a strong seawater contribution. Previous numerical simulations of fluid flow and heat transport indicated that focused upsurge of hot water in faults induces a convective-like flow motion in surrounding units. Salt transport is fully coupled to thermally driven flow to study whether fault-induced convection cells could be responsible for seawater encroachment in the SBG. Isotope data are presented to support the numerical findings. The results show that fault-induced convection cells generate seawater plumes that extend from the seafloor toward the faults. At fault intersections, seawater mixes with rising hot thermal waters. The resulting saline fluids ascend to the surface along the fault, driven by buoyant forces. In Bal double dagger ova, thick alluvium, minor faults and regional flow prevent ascending salty water from spreading at the surface, whereas the weak recharge flow in the thin alluvium of the southern SBG is not sufficient to flush the ascending hot salty waters. These mechanisms could develop in any faulted geothermal system, with implications for minerals and energy migration in sedimentary basins.