Anomalous Strong Reflections on High Resolution Seismic Data from the Turkish Shelf of the Eastern Black Sea: Possible Indicators of Shallow Hydrogen Sulphide-Rich Gas Hydrate Layers

DONDURUR D., Cifci G.

TURKISH JOURNAL OF EARTH SCIENCES, cilt.18, sa.2, ss.299-313, 2009 (SCI-Expanded) identifier identifier

  • Yayın Türü: Makale / Tam Makale
  • Cilt numarası: 18 Sayı: 2
  • Basım Tarihi: 2009
  • Doi Numarası: 10.3906/yer-0801-1
  • Dergi Adı: TURKISH JOURNAL OF EARTH SCIENCES
  • Derginin Tarandığı İndeksler: Science Citation Index Expanded (SCI-EXPANDED), Scopus, TR DİZİN (ULAKBİM)
  • Sayfa Sayıları: ss.299-313
  • Anahtar Kelimeler: Black Sea, gas hydrate, hydrogen sulphide, high-resolution acoustic methods, CONTINENTAL-MARGIN SEDIMENTS, SULFATE REDUCTION, DEEP-WATER, METHANE OXIDATION, TRACE-METALS, SULFUR, SLOPE, IRON, SPECIATION, STABILITY
  • Dokuz Eylül Üniversitesi Adresli: Evet

Özet

Some strong reflections about 3 to 5 m thick were observed at depths of 25-60 metres below the sea floor using deep-towed, 5 kHz subbottom profiler data in the Turkish shelf and upper slope of the Eastern Black Sea at water depths of 250 to 700 m. Strong reflections of this kind are generally attributed to shallow and localized gas accumulations. We, however, observed that the reflection polarity of these strong reflections was positive, suggesting that they do not correspond to reflections from the upper boundary of a possible gas front. In this study, we evaluate these reflections to determine if they represent hydrogen sulphide-rich shallow gas hydrate layers, which would be an unusual gas hydrate occurrence in a shallow marine environment.