title: Fast retreat of Zachariæ Isstrøm, northeast Greenland.
abstract: After 8 years of decay of its ice shelf, Zachariæ Isstrøm, a major glacier of northeast Greenland that holds a 0.5-meter sea-level rise equivalent, entered a phase of accelerated retreat in fall 2012. The acceleration rate of its ice velocity tripled, melting of its residual ice shelf and thinning of its grounded portion doubled, and calving is now occurring at its grounding line. Warmer air and ocean temperatures have caused the glacier to detach from a stabilizing sill and retreat rapidly along a downward-sloping, marine-based bed. Its equal-ice-volume neighbor, Nioghalvfjerdsfjorden, is also melting rapidly but retreating slowly along an upward-sloping bed. The destabilization of this marine-based sector will increase sea-level rise from the Greenland Ice Sheet for decades to come.
authors.affiliation: Department of Earth System Science, University of California, Irvine, CA 92697, USA. jmougino@uci.edu.
authors.forename: J
authors.initials: J
authors.lastname: Mouginot
authors.affiliation: Department of Earth System Science, University of California, Irvine, CA 92697, USA. Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA 91109-8099, USA.
authors.forename: E
authors.initials: E
authors.lastname: Rignot
authors.affiliation: Department of Earth System Science, University of California, Irvine, CA 92697, USA.
authors.forename: B
authors.initials: B
authors.lastname: Scheuchl
authors.affiliation: Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA 91109-8099, USA.
authors.forename: I
authors.initials: I
authors.lastname: Fenty
authors.affiliation: Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA 91109-8099, USA.
authors.forename: A
authors.initials: A
authors.lastname: Khazendar
authors.affiliation: Department of Earth System Science, University of California, Irvine, CA 92697, USA.
authors.forename: M
authors.initials: M
authors.lastname: Morlighem
authors.affiliation: Department of Earth System Science, University of California, Irvine, CA 92697, USA.
authors.forename: A
authors.initials: A
authors.lastname: Buzzi
authors.affiliation: Center for Remote Sensing of Ice Sheets, University of Kansas, Lawrence, KS 66045, USA.
authors.forename: J
authors.initials: J
authors.lastname: Paden