Passive MarginActive MarginSiberian Margin
A passive (nonsubducting) continental margin simulation based on the Atlantic coast of the United States. Left panel includes the impact of vertical chimneys of high permeability, right panel assumes lateral homogeneity. Color scales show dissolved methane concentration. Sea level and the boundary of the methane hydrate stabililty zone are also shown in black lines. An active (subducting) margin modeled after the Pacific coast of Canada (Vancouver Island). The underlying ocean crust is subducting to the left, and the sediment is deformed into an accretionary grid. Variant to the right assumes lateral variation in the deformability of the sediment column, leading to irregular lateral compression. Color scales show dissolved methane concentration. Sea level and the boundary of the methane hydrate stabililty zone are also shown in black lines. A simulation of the Siberian continental margin after glacial sea level drop and exposure to the cold atmosphere, snapshot as sea level rises during the deglaciation. The colors indicate dissolved methane concentration. Red contours show the ice fraction in permafrost. The black contour shows the limits of the methane hydrate stability zone. The movies (after the first two) show four 100-kyr sawtooth-shaped glacial/interglacial cycles (62-62.4 Myr) followed by 100 kyr of a global warming scenario (62.4-62.5 Myr). The first deglaciation (62.08-62.1 Myr) zooms in in time, with frames from 10 times as often through the simulation.
Archer, D.E., B.A. Buffett, and P.C. McGuire (2012). A two-dimensional model of the passive coastal margin deep sedimentary carbon and methane cycles. Biogeosciences., 9, 1-20, doi:10.5194/bg-9-1-2012, 2012
Archer, D.E. and B.A. Buffett (2012) A two-dimensional model of the methane cycle in a sedimentary accretionary wedge. Biogeosciences, 9, 3323–3336, 2012
Archer, D.E. (2014) A model of the methane cycle, permafrost, and hydrology of the Siberian continental margin Biogeosciences Discuss 11, 7853-7900, 2014
Movies
Sensitivity Studies
Movies show the variant on the right, compared with the base case on the left. Four glacial cycles span the first 400,000 years, followed by 100,000 of "Anthropocene".
HydrateBubblesCH4 FluxSalinity
Initial Salinity (Marine vs. Fresh Base) link link link link
Thermogenic methane x10 link link link link
Thermogenic methane x100 link link link link
Land POC Deposition x3 link link link link
Land POC Deposition x10 link link link link
Geotherm x 50% link link link link
Geotherm x 75% link link link link
Geotherm x 125% link link link link
Geotherm x 150% link link link link
Bubble Migration @ Ice 10% link link link link
Bubble Migration @ Ice 30% link link link link
Bubble Migration @ Ice 70% link link link link
Bubble Migration @ Ice 90% link link link link
Ice Formation Disallowed link link link link
Hydrate Sees Salinity 35 PSU link link link link
Vertical Permeable Channels link link link link
Horizontal Flow Disabled link link link link