Thessaloniki Mud Volcano, the Shallowest Gas Hydrate-Bearing Mud Volcano in the Anaximander Mountains, Eastern Mediterranean

Abstract

A detailed multibeam survey and the subsequent gravity coring carried out in the Anaximander Mountains, Eastern Mediterranean, detected a new active gas hydrate-bearing mud volcano (MV) that was named Thessaloniki. It is outlined by the 1315 m bathymetric contour, is 1.67 km2 in area, and has a summit depth of 1260 m. The sea bottom water temperature is . The gas hydrate crystals generally have the form of flakes or rice, some larger aggregates of them are up to 2 cm across. A pressure core taken at the site contained 3.1 lt. of hydrocarbon gases composed of methane, nearly devoid of propane and butane. The sediment had a gas hydrate occupancy of 0.7% of the core volume. These characteristics place the gas hydrate field at Thessaloniki MV at the upper boundary of the gas hydrate stability zone, prone to dissociation with the slightest increase in sea water temperature, decrease in hydrostatic pressure, or change in the temperature of the advecting fluids.

Methane Hydrate Stability and Potential Reserves in the Levant Basin, Southeastern Mediterranean Sea

“…The main purpose of this study is to review possible evidence and constrain the potential for [75,76]. [75] argued that this occurs at the top boundary of their modeled GHSZ, considering very similar local thermodynamic conditions to those used by us.…”

Submarine vortices derived from natural gas hydrate conversion: a mechanism for ocean mixing

“…This is about twice as deep than in the cooler global open ocean (Max & Johnson, 2016). Significant NGH deposits also exist beneath the seafloor, and have been identified in the Mediterranean Basin by seismic interpretation and in-situ (De Lange & Brumsack, 1998;Aloisi et al, 2000;Loncke et al, 2004;Pierre & Rouchy, 2004;Dählmann, 2005;Lykousis et al, 2009;Perissoratis et al, 2011;Marinakis et al, 2015), and in the Nile fan (Praeg et al, 2011). Global models of NGH thicknesses indicate a 100 -250 m thick gas hydrate stability zone (GHSZ) in the Mediterranean region (Wood & Jung, 2008) (Fig.…”

“…East Coast continental slope (Paull et al, 1996;Paull et al, 1998;Holbrook, 2001;Paull & Ussler, 2001;Hesse, 2003). When NGH dissociates in an endothermic reaction, an approximately equal amount of heat per comparable volume of NGH is absorbed from surrounding sediments, as low-salinity water and gas are produced.…”

Mud volcanism of mediterranean, Black and Caspian seas: specificity of development and manifestations

“…В прибрежной части юго западной Турции -в горах Анаксимена и Анаксо гора, входящих в состав подводных Анаксимандрских гор, на глубинах 1315-2025 м установлено 7 вулканов высотой 50 м и диаметром основания 1750 м. К северу и северо западу от Амстердамского вулкана на глубине 1300 м, на площади 15х15 км обнаружено более 25 изолированных куполов в диаметре 0,3-1,0 км и высотой 200-500 м [30,38].…”