Active seafloor processes in the Levant: observations and potential - PowerPoint PPT Presentation

Active seafloor processes in the Levant: observations and potential implications Makovsky Y. (1), G. Tibor (2), B. Herut (2), U. Schattner (1), D.N. Waldmann (1), Spiro B. (1), Sivan O. (3), Antler G. (3), Ballard R.D. (4), Austin J. (4), Coleman D. (4), Tezcan D. (1), Hübscher C. (5), and Ben-Avraham Z. (1). 1. Charney School of Marine Sciences (CSMS), University of Haifa, Israel. 2. Israel Oceanographic and Limnological Research, Haifa, Israel 3. Geological and Environmental Sciences, Ben-Gurion University of the Negev, Beer-Sheva, Israel. 4. Sea Research Foundation Institute for Exploration, Institute for Exploration, Mystic, RI, USA. 5. Institute for Geophysics, CMCR, University of Hamburg, Hamburg, Germany. Acknowledgements IFE and University of Haifa for funding; The Oil Commissioner office for data approval Paradigm for software support E/V Nautilus crew and project participants Noble Energy, GGR, Modiin, Ecolog, Israel Ministry of Energy and water for data and slides John Hall, Israel Bathymetric survey

Unprecedented Levant offshore exploration & infrastructure development:  A need for basic understanding  Global technical challenges  Environmental concerns Sustainable development requires: • Data sharing • A wide industry-government-academy collaboration.

Two collaborative ROV cruises of E/V Nautilus investigated, in 2010 and 2012 the deep Mediterranean offshore of Israel at water depths of 500-1700 m

Bathymetry of the deep offshore of Israel Hall, 1980

Bathymetry of the deep offshore of Israel Hall and Sade, 2008

Bathymetry of the deep offshore of Israel IBS & IOLR 2012

Bathymetry of the deep offshore of Israel 3D seismics + Tamar Site Survey The eastern turbidite channel

The western edge of Palmahim Disturbance 3D seismic Multibeam The turbidite channel is truncated by salt related faulting

ROV surveying of the channel near Tamar Noble Energy

The western edge of Palmahim Disturbance 3D seismic Multibeam The southern fault of Palmahim Disturbance

The Palmahim Disturbance is an apparently-active rotational slide Garfunkel et al., 1979 Hampton et al. (1996)

Ongoing activity of the Palmahim Disturbance Joint CU-BGU-IOLR-UH cruise, May 2011 100 150 Approximate Depth [m] 120 140 Two Way Time [msec] 200 160 180 250 200 300 350 Horizontal scale [km] 0 1 2 Garfunkel et al., 1979

A preliminary depth migrated section through the Palmahim Disturbance Yaniv Marig MSC

An opportunity to investigate the Messinian salt

Deformation zones within the continental margin of Israel Murad Safadi MSC

Seafloor stability and submarine slides pose major geohazards to infrastructure development Mari-B Noa pipeline Pinnacles 2012 Yam W 01 Or S 01 Wells and Noa S 01 Or 01 Noa 01 Yam W 02 Andromeda E 01 Frey-Martinez et al., 2005 ~5 km

Shallow gas accumulations and Garfunkel et al., 1979 seepage at the toe of Palmahim Disturbance N ~5 km Large scale pockmarks Pockmark Bright spot reflection 1 km

Active seafloor gas seeps at the toe of Palmahim Disturbance Water depth ~1100m

Preliminary analysis of push- core and Niskin interstitial, surface and above-seafloor water reveal: • high concentrations of methane • Carbon isotopic values suggesting a biogenic origin • oxygen depletion in near surface water • Si enrichment at the seafloor Gilad Antler & Orit Sivan 7 6 Ni ( μ mol/L) 5 N:Si = 16:15 (Brzezinski, 1985) Nitrate ( m mol/L) Ni:Si = 16:15 (Brzezinski, 1985) Above the y = 0.58x + 0.42 4 R 2 = 0.93 seafloor 3 2 Jack Silverman 1 At the seafloor & Niv David 0 0 2 4 6 8 10 Si ( μ mol/L) Silicate ( m mol/L)

Garfunkel et al., 1979 Hard rock reefs at water depths of 600-800 m host an oasis of biodiversity, primarily Antipatharian and Grogonian corals Water depth 700m Water depth 780m

Preliminary analysis of a tubular rock sample suggests a methanogenic origin Sulphide – pyrite in SEM scan attesting bacterial reduction Oxygen an Carbon isotopes in Pal 2 NA009 49D AHDFA Oxygen and Carbon isotopes attesting oxidation of CH4 -24 d13C (permil vrs PDB) -26 -28 -30 -32 -34 -36 -38 -40 5.0 5.2 5.4 5.6 5.8 6.0 Baruch Spiro d18O (permil vrs PDB)

Akko Haifa Active methane seepage in seafloor pockmarks offshore Akko Water depth 1100m

Other possible evidence of methane seepage along the edges of the Levant basin still need to be investigated Offshore Israel Eratosthenes Sea Mount (Mayer et al., 2011)

Methane seepage is now found in a rim around much of the Levant basin

Several apparent gas shows within the post Messinian section

So what about hydrates? Hydrate stability models Gas seeps vs. seismic reflectivity 1. 1 2 3 2. A depositional system? 3.

Isr Israe ael l Cen Center ter of of Medite Mediterran anea ean n Se Sea a Res esea earch Pulling together interdisciplinary expertise and modern research infrastructure at the national level. Environmental Resources Remote sensing Management Political Sciences Archaeology & History Economics Engineering & Technology Maritime Law Biology Physical & chemical Oceanography Geology & Geophysics

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Shallow gas on the Mediterranean shelf offshore Israel High amplitude reflections in sparker profiles The extent of the gas layer offshore Israel Schattner et al., 2012 Neev et al., 1966 Golan, 2006: Golan, 2006 • Analysis of cores samples indicate the presence of Methane, probably of biogenic origin.

Characterizing shallow gas on Haifa Bay reflection profiles Northern Bay of Haifa Survey Line-20 Approximate distance along profile [m] 0 80 160 240 320 400 480 560 640 720 800 Pock mark? 48 36 52 39 Approximate depth [m] Seismic Scattered high amplitude Two-way-time [msec] ‘ bright spot ’ 56 42 reflectivity 60 45 64 48 68 51 A gas bearing stretch is present within the layered sediments Stretched reflections 72 54

Evaluating gas content Northern Bay of Haifa Survey - Line-20 • Examining the specular reflections by removal of the diffuse reflectivity (low-pass filter + lateral mix) Approximate distance along profile [m] 0 80 160 240 320 400 0 80 160 240 320 400 42 60 48 Approximate depth [m] Two-way-time [msec] 68 54 76 60 84 66 The high amplitude reflections are actually concentrated in a ~6 m wide gas-bearing section

Evaluating gas content Northern Bay of Haifa Survey - Line-20 • Examining the specular reflections by removal of the diffuse reflectivity (low-pass filter + lateral mix) Approximate distance along profile [m] 0 80 160 240 320 400 0 80 160 240 320 400 42 60 48 Approximate depth [m] Two-way-time [msec] 68 54 76 60 84 66

Migration of gas in granular sediments Invasion by: a. Capillary pressure b. Fracture opening Jain & Juanes (2009) Bubble tracks in a. Silty sands b. clay Best et al. (2004)

Haifa Bay A gas front within the shallow sediments 40 Corrected time [msec] ~1 km 60 80 100 120 Surface-A Surface-A

The bubbles dissolve as the ascend until they disappear and the methane is consumed Whiticar (2002)

Picks of Top Gas w/r to Surface-A overlaid on a map of Surface-A w/r to the seafloor

Picks of Top Gas w/r to the seafloor overlaid on a map of Surface-A w/r to the seafloor A zoom on the highly variable southwest corner of the study area