Mud Volcanoes in the South Caspian Basin: Activity Inferred From ENVISAT ASAR Images Martin Weinelt & Warner Brückmann Helmholtz Centre for Ocean Research Kiel 1
Mud Volcanoes in the South Caspian Basin MV Occurrence onshore More than 1100 worldwide - ~50% Caspian Sea Area M.Weinelt & W. Brückmann GEOMAR Kiel 2
On-shore GE M.Weinelt & W. Brückmann GEOMAR Kiel 3
Driving mechanism: - Sediment overpressure - High rates of accumulation - Tectonically induced compression - Relative vertical movement Resulting in: Water and gas (~80% methane) forced up to the surface M.Weinelt & W. Brückmann GEOMAR Kiel 4
Driving Mechanisms cntd. - Overpressure - Gaseous phase (methane) Example of a large anticlinal structure with an active mud volcano complex within a structurally controlled collapse depression and large recent flows (>9 km) and two generations of sidewall slumping, Nakhchivan anticline, western SCB. (modified from Corthay and Aliyev,2000) M.Weinelt & W. Brückmann GEOMAR Kiel 5
Mud Volcanoes in the South Caspian Basin MV off-shore MV North Alex, Nile Delta off Egypt (J. Bialas, GEOMAR) M.Weinelt & W. Brückmann GEOMAR Kiel 6
Mud Volcanoes at the Sea Floor Gas flares from the seafloor North Alex (Nile Delta) M.Weinelt & W. Brückmann GEOMAR Kiel 7
Nice, so what hazards? - Ground instability and motion - Fluid and gas flow - Climatic impact (greenhouse gas) Source: Institute of Geology of the Azerbaijan Academy of Science M.Weinelt & W. Brückmann GEOMAR Kiel 8
Selected SAR Scenes (ENVISAT) Basemap: Open Street Map (CC by/sa) M.Weinelt & W. Brückmann GEOMAR Kiel 9
Mud Volcanoes in the South Caspian Basin Plate collision outline Outline of plate motion and direction (white arrows) and strike-slip faults (black half-arrows); (Smith-Rouch 2006 based on Berberian 1983) M.Weinelt & W. Brückmann GEOMAR Kiel10
Mud Volcanoes in the South Caspian Basin Compressional Regime Caspian Area Mesozoic-Neogene plate reconstruction closure of Tethys ocean (Golonka, 2007) M.Weinelt & W. Brückmann GEOMAR Kiel 11
Mud Volcanoes in the South Caspian Basin Huge Pile of Accretionary Sediments Depth to basement south of Aspheron ridge: > 20km (Green et al, 2009) M.Weinelt & W. Brückmann GEOMAR Kiel12
Spotting MV from long distance: 1: Physiographic hints The typical shape Narrow range DEM rendering SCB GRSG/OGEO Workshop 2011 Kiel M.Weinelt & W. Brückmann GEOMAR 13
Spotting MV from Long Distance: DEM Analysis Raster Data Analysis: Aspect (Slope, Ruggedness,...) Contouring GRSG/OGEO Workshop 2011 Kiel M.Weinelt & W. Brückmann GEOMAR 14
~ 270 MV Suspects identified Circles: MV already mapped (Dadachev et al, 1995) Diamonds: Suspects derived from DEM GRSG/OGEO Workshop 2011 Kiel M.Weinelt & W. Brückmann GEOMAR 15
Spotting MV from long distance: 2: Natural Oil Slicks ESA / ENVISAT M.Weinelt & W. Brückmann GEOMAR Kiel16
Radar Scene Selection Weather information ESA Archive Selected scenes M.Weinelt & W. Brückmann GEOMAR Kiel17
Imaging Control: Wind Speed ENVISAT ASAR images south east off Baku showing the effect of different wind conditions on SAR imagery. Top left: with very slight or no wind large areas of very low backscatter occur (close to the coast) or spiral eddies (currents) overprint oil-slicks. Top right: the preferable wind speed window ambient backscatter is sufficiently intensive to clearly show oil slicks or patches in the vicinity of offshore oil-installations east of the Absheron peninsula. The switch from northwesterly to northerly wind directions is clear in the oil slick track. Bottom left: High wind regime. Oil slicks may get almost completely undetectable by intensified wave action or damping becomes ineffective in terms of the ASAR imagery. SAR Images: ESA M.Weinelt & W. Brückmann GEOMAR Kiel18
SAR Image: ESA Registration Date 0 8/29/2005 Wind Conditions NNW 7.2 m/s Weather Station Baku (dist. 60km) Image Patterns Preferable wind conditions result in high contrast imaging of oil slicks mostly due to pollution around oil installations. Westernmost streaks: potentially from seafloor seepage. M.Weinelt & W. Brückmann GEOMAR Kiel19
SAR Image: ESA Registration Date 2004-12- 21 Wind Conditions ENE 2.0 m/s Weather Station Turkmenbashi (dist. 45km) Image Patterns Despite the low wind regime the imaging quality of the scene in terms of contrasting patterns is very good. Low wind speed leads to large low backscatter areas off the cost Turkmenistan and associated spiral patterns. Straight west of Cheleken a ~27km long and ~150m to 250m wide slick is clearly detected. Bright pixels in the vicinity represent off-shore installations. M.Weinelt & W. Brückmann GEOMAR Kiel20
SAR Image: ESA Registration Date 0 8/29/2005 Wind Conditions NNW 7.2 m/s Weather Station Baku (dist. 60km) Image Patterns Preferable wind conditions result in high contrast imaging of oil slicks mostly due to pollution around oil installations. Westernmost streaks: potentially from seafloor seepage. M.Weinelt & W. Brückmann GEOMAR Kiel21
SAR Image: ESA Registration Da te 0 9/17/2005 Wind Conditions N 6.2 m/s Weather Station Baku (dist. 200km) Image Patterns Good contrast image. More than 25 dark streaks (natural oil slicks) roughly oriented according to the wind direction. M.Weinelt & W. Brückmann GEOMAR Kiel22
SAR Image: ESA Registration Date 0 9/17/2005 Wind Conditions WNW 2.0 Weather Station Rasht (dist. 100km) Image Patterns Low wind causes low backscatter close to the coast and for central parts of the area. Local front and eddy patterns dominate the image. Dog leg -shaped streaks at the eastern part of the area display a typical oil slick shape. M.Weinelt & W. Brückmann GEOMAR Kiel23
SAR Image: ESA Registration Date 11 /26/2005 Wind Conditions S 6.0 Weather Station Baku (dist. 45km) Image Patterns Good contrast between ambient backscatter and oil covered surface areas. Dark patches very prominent around industry installations off-shore. 4 to 5 slicks of ~3km to 4km length at the southern edge of the scene obviously unrelated to oil production installations. M.Weinelt & W. Brückmann GEOMAR Kiel24
Indicative Patterns M.Weinelt & W. Brückmann GEOMAR Kiel25
Conclusions: Results presented here are from a 9 month pilot study Project initiated in November 2011 First field work in next year. GRSG/OGEO Workshop 2011 Kiel M.Weinelt & W. Brückmann GEOMAR 26
Sponsoring partners GRSG/OGEO Workshop 2011 Kiel M.Weinelt & W. Brückmann GEOMAR 27