title: Arctic megaslide at presumed rest.
abstract: Slope failure like in the Hinlopen/Yermak Megaslide is one of the major geohazards in a changing Arctic environment. We analysed hydroacoustic and 2D high-resolution seismic data from the apparently intact continental slope immediately north of the Hinlopen/Yermak Megaslide for signs of past and future instabilities. Our new bathymetry and seismic data show clear evidence for incipient slope instability. Minor slide deposits and an internally-deformed sedimentary layer near the base of the gas hydrate stability zone imply an incomplete failure event, most probably about 30000 years ago, contemporaneous to or shortly after the Hinlopen/Yermak Megaslide. An active gas reservoir at the base of the gas hydrate stability zone demonstrate that over-pressured fluids might have played a key role in the initiation of slope failure at the studied slope, but more importantly also for the giant HYM slope failure. To date, it is not clear, if the studied slope is fully preconditioned to fail completely in future or if it might be slowly deforming and creeping at present. We detected widespread methane seepage on the adjacent shallow shelf areas not sealed by gas hydrates.
authors.affiliation: Alfred-Wegener-Institut Helmholtz-Zentrum für Polar- und Meeresforschung, Bremerhaven, Germany.
authors.forename: Wolfram H
authors.initials: WH
authors.lastname: Geissler
authors.affiliation: Alfred-Wegener-Institut Helmholtz-Zentrum für Polar- und Meeresforschung, Bremerhaven, Germany.
authors.forename: A Catalina
authors.initials: AC
authors.lastname: Gebhardt
authors.affiliation: Christian-Albrechts-Universität, Kiel, Germany.
authors.forename: Felix
authors.initials: F
authors.lastname: Gross
authors.affiliation: Alfred-Wegener-Institut Helmholtz-Zentrum für Polar- und Meeresforschung, Bremerhaven, Germany.
authors.forename: Jutta
authors.initials: J
authors.lastname: Wollenburg
authors.affiliation: Alfred-Wegener-Institut Helmholtz-Zentrum für Polar- und Meeresforschung, Bremerhaven, Germany.
authors.forename: Laura
authors.initials: L
authors.lastname: Jensen
authors.affiliation: Alfred-Wegener-Institut Helmholtz-Zentrum für Polar- und Meeresforschung, Bremerhaven, Germany.
authors.forename: Mechita C
authors.initials: MC
authors.lastname: Schmidt-Aursch
authors.affiliation: Christian-Albrechts-Universität, Kiel, Germany.
authors.forename: Sebastian
authors.initials: S
authors.lastname: Krastel
authors.affiliation: GEOMAR Helmholtz-Zentrum für Ozeanforschung, Kiel, Germany.
authors.forename: Judith
authors.initials: J
authors.lastname: Elger
authors.affiliation: CAGE - Centre for Arctic Gas Hydrate, Environment and Climate, Department of Geology, UiT-The Arctic University of Norway, Tromsø, Norway.
authors.forename: Giacomo
authors.initials: G
authors.lastname: Osti