Preliminary ASTER and INSAR imagery combination for mud volcano dynamics, Azerbaijan

Abstract

In Azerbaijan oil mud volcanoes form on the surface as expressions of the vertical migration of oil and gas as a result of gravitationa l loading of largely unconsolidated sediments in combination with structure control and stress regime. In general it is believed that mud volcano eruptions are triggered by earthquake activity since this can cause hydrate instability and explosive dissociation of the hydrocarbons can occur. Through typical geomorphologic mud volcano vents called gryphons and salses, mud volcanoes eject argillaceous material (breccia) and build up their topography. Optical satellite images (Advanced Spaceborne Thermal Emission and Reflection - ASTER) and ground truth data from 2000 to 2002, centred on onshore Azerbaijan, are analysed using Variable Multiple Endmember Spectral Mixture Analysis (VMESMA) in combination with Interferometric Synthetic Aperture Radar (InSAR) from six ERS-2 scenes from 1996 to 1999. ASTER and InSAR imagery are used to look for evidence of mineral alterations and precursory surface deformation related to mud volcanism. Preliminary field spectral data of 5 onshore mud volcano vents show typical mineral zonations present in the mud breccia fields. ASTER image analyses on Aktharma -Pashaly mud volcano shows Al-OH mineral zonation patterns over various mud volcano vents. Initial InSAR processing for Aktharma-Pashaly shows little correlation over this particular mud volcano, which makes it hard to assess data combinations of ASTER and InSAR. Fair correlation was found for Touragai, Great - and Lesser Kjanizadag mud volcanoes showing high to moderate correlation over a time period of 3 years.