Morlighem Mathieu

No Thumbnail Available
Last Name
Morlighem
First Name
Mathieu
ORCID
0000-0001-5219-1310

Filters

2016 - 2019 2 2020 - 2023 2
4
4
Reset filters

Settings

Search Results

Now showing 1 - 4 of 4
  • Article
    BedMachine v3 : complete bed topography and ocean bathymetry mapping of Greenland from multibeam echo sounding combined with mass conservation
    (John Wiley & Sons, 2017-11-01) Morlighem, Mathieu ; Williams, Chris N. ; Rignot, Eric ; An, Lu ; Arndt, Jan Erik ; Bamber, Jonathan L. ; Catania, Ginny ; Chauché, Nolwenn ; Dowdeswell, Julian ; Dorschel, Boris ; Fenty, Ian ; Hogan, Kelly ; Howat, Ian M. ; Hubbard, Alun ; Jakobsson, Martin ; Jordan, Tom M. ; Kjeldsen, Kristian K. ; Millan, Romain ; Mayer, Larry A. ; Mouginot, Jeremie ; Noël, Brice P. Y. ; O’Cofaigh, Colm ; Palmer, Steven ; Rysgaard, Soren ; Seroussi, Helene ; Siegert, Martin J. ; Slabon, Patricia ; Straneo, Fiamma ; Van den Broeke, Michiel ; Weinrebe, W. ; Wood, Michael ; Zinglersen, Karl Brix
    Greenland's bed topography is a primary control on ice flow, grounding line migration, calving dynamics, and subglacial drainage. Moreover, fjord bathymetry regulates the penetration of warm Atlantic water (AW) that rapidly melts and undercuts Greenland's marine-terminating glaciers. Here we present a new compilation of Greenland bed topography that assimilates seafloor bathymetry and ice thickness data through a mass conservation approach. A new 150 m horizontal resolution bed topography/bathymetric map of Greenland is constructed with seamless transitions at the ice/ocean interface, yielding major improvements over previous data sets, particularly in the marine-terminating sectors of northwest and southeast Greenland. Our map reveals that the total sea level potential of the Greenland ice sheet is 7.42 ± 0.05 m, which is 7 cm greater than previous estimates. Furthermore, it explains recent calving front response of numerous outlet glaciers and reveals new pathways by which AW can access glaciers with marine-based basins, thereby highlighting sectors of Greenland that are most vulnerable to future oceanic forcing.
  • Article
    Characteristic depths, fluxes and timescales for Greenland’s tidewater glacier fjords from subglacial discharge‐driven upwelling during summer
    (American Geophysical Union, 2022-03-02) Slater, Donald A. ; Carroll, Dustin ; Oliver, Hilde ; Hopwood, Mark J. ; Straneo, Fiamma ; Wood, Michael ; Willis, Joshua K. ; Morlighem, Mathieu
    Greenland's glacial fjords are a key bottleneck in the earth system, regulating exchange of heat, freshwater and nutrients between the ice sheet and ocean and hosting societally important fisheries. We combine recent bathymetric, atmospheric, and oceanographic data with a buoyant plume model to show that summer subglacial discharge from 136 tidewater glaciers, amounting to 0.02 Sv of freshwater, drives 0.6–1.6 Sv of upwelling. Bathymetric analysis suggests that this is sufficient to renew most major fjords within a single summer, and that these fjords provide a path to the continental shelf that is deeper than 200 m for two-thirds of the glaciers. Our study provides a first pan-Greenland inventory of tidewater glacier fjords and quantifies regional and ice sheet-wide upwelling fluxes. This analysis provides important context for site-specific studies and is a step toward implementing fjord-scale heat, freshwater and nutrient fluxes in large-scale ice sheet and climate models.
  • Article
    Linking glacially modified waters to catchment-scale subglacial discharge using autonomous underwater vehicle observations
    (Copernicus Publications on behalf of the European Geosciences Union, 2016-02-24) Stevens, Laura A. ; Straneo, Fiamma ; Das, Sarah B. ; Plueddemann, Albert J. ; Kukulya, Amy L. ; Morlighem, Mathieu
    Measurements of near-ice (<  200 m) hydrography and near-terminus subglacial hydrology are lacking, due in large part to the difficulty in working at the margin of calving glaciers. Here we pair detailed hydrographic and bathymetric measurements collected with an autonomous underwater vehicle as close as 150 m from the ice–ocean interface of the Saqqarliup sermia–Sarqardleq Fjord system, West Greenland, with modeled and observed subglacial discharge locations and magnitudes. We find evidence of two main types of subsurface glacially modified water (GMW) with distinct properties and locations. The two GMW locations also align with modeled runoff discharged at separate locations along the grounded margin corresponding with two prominent subcatchments beneath Saqqarliup sermia. Thus, near-ice observations and subglacial discharge routing indicate that runoff from this glacier occurs primarily at two discrete locations and gives rise to two distinct glacially modified waters. Furthermore, we show that the location with the largest subglacial discharge is associated with the lighter, fresher glacially modified water mass. This is qualitatively consistent with results from an idealized plume model.
  • Article
    Greenland Subglacial Discharge as a driver of hotspots of increasing coastal chlorophyll since the early 2000s
    (American Geophysical Union, 2023-05-18) Oliver, Hilde ; Slater, Donald ; Carroll, Dustin ; Wood, Michael ; Morlighem, Mathieu ; Hopwood, Mark J.
    Subglacial discharge emerging from the base of Greenland's marine‐terminating glaciers drives upwelling of nutrient‐rich bottom waters to the euphotic zone, which can fuel nitrate‐limited phytoplankton growth. Here, we use buoyant plume theory to quantify this subglacial discharge‐driven nutrient supply on a pan‐Greenland scale. The modeled nitrate fluxes were concentrated in a few critical systems, with half of the total modeled nitrate flux anomaly occurring at just 14% of marine‐terminating glaciers. Increasing subglacial discharge fluxes results in elevated nitrate fluxes, with the largest flux occurring at Jakobshavn Isbræ in Disko Bay, where subglacial discharge is largest. Subglacial discharge and nitrate flux anomaly also account for significant temporal variability in summer satellite chlorophyll a (Chl) within 50 km of Greenland's coast, particularly in some regions in central west and northwest Greenland.Runoff and modeled nitrate upwelling can explain temporal variability in surface cholorophyll in some coastal areas in west Greenland