Abstract
The distribution of gas hydrates recently raised increased attention, especially along glaciated continental margins, due to its potential importance for slope stability and global climate. We present new heat flow data together with multichannel reflection seismic data from the central Fram Strait in-between Northeast Greenland and Svalbard. This area is only accessible by icebreaking vessels, and, therefore, knowledge about this area is still sparse. The new heat flow data concur with previous measurements in the region. High temperature gradients of >200 mK/m were recorded along the active spreading zone in the Fram Strait, and gradients of 75 mK/m along the western slope of Yermak Plateau. Along the Northeast Greenland slope, the measured gradients reach 54 mK/m at maximum. Seismic data image bottom-simulating reflections proofing that the known gas-hydrate province spreads much further north along the western slope of the Yermak Plateau than previously known. Existing slide scars indicate that there might be a causal relationship between the occurrence of gas hydrates and slope instability in that area. Along the Northeast Greenland continental margin and in the adjacent abyssal plain, strong indications for the occurrence of gas within the sedimentary basins and for its migration along fault zones and chimney-like structures are found.
Highlights
During the last years the scientific interest on gas hydrates and their worldwide occurrences constantly grew
We present new heat flow data together with multichannel reflection seismic data from the central Fram Strait in-between Northeast Greenland and Svalbard
It is obvious that high values follow the mid ocean ridges, while the old, cold continental crust beneath the shelf area is characterized by low temperature gradients
Summary
During the last years the scientific interest on gas hydrates and their worldwide occurrences constantly grew. Gas hydrates are an ice-like substrate consisting of light hydrocarbons (mostly methane), which are trapped in the lattice of water molecules [2]. They occur all over the world at both rifted and active margin settings. Gas hydrates along glaciated margins might react extremely sensitive to changes in bottom-water temperatures and, climate change [3]. They represent a significant geohazard, because their occurrence is closely linked to slope stability [4]. The escape of methane may contribute to methane anomalies in the atmosphere as discussed, for example, in Hustoft et al [7] and Gentz et al [8]
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