ORCID Profile
0000-0002-6669-4557
Current Organisations
Earth and Space Research
,
University of Washington
Does something not look right? The information on this page has been harvested from data sources that may not be up to date. We continue to work with information providers to improve coverage and quality. To report an issue, use the Feedback Form.
Publisher: Wiley
Date: 29-07-2020
Publisher: Springer Science and Business Media LLC
Date: 27-05-2019
Publisher: Proceedings of the National Academy of Sciences
Date: 08-2011
Abstract: Episodic iceberg-discharge events from the Hudson Strait Ice Stream (HSIS) of the Laurentide Ice Sheet, referred to as Heinrich events, are commonly attributed to internal ice-sheet instabilities, but their systematic occurrence at the culmination of a large reduction in the Atlantic meridional overturning circulation (AMOC) indicates a climate control. We report Mg/Ca data on benthic foraminifera from an intermediate-depth site in the northwest Atlantic and results from a climate-model simulation that reveal basin-wide subsurface warming at the same time as large reductions in the AMOC, with temperature increasing by approximately 2 °C over a 1–2 kyr interval prior to a Heinrich event. In simulations with an ocean model coupled to a thermodynamically active ice shelf, the increase in subsurface temperature increases basal melt rate under an ice shelf fronting the HSIS by a factor of approximately 6. By analogy with recent observations in Antarctica, the resulting ice-shelf loss and attendant HSIS acceleration would produce a Heinrich event.
Publisher: Wiley
Date: 09-06-2020
Publisher: Cambridge University Press (CUP)
Date: 03-08-2020
DOI: 10.1017/JOG.2020.61
Abstract: Ice shelves play a critical role in modulating dynamic loss of ice from the grounded portion of the Antarctic Ice Sheet and its contribution to sea-level rise. Measurements of ice-shelf motion provide insights into processes modifying buttressing. Here we investigate the effect of seasonal variability of basal melting on ice flow of Ross Ice Shelf. Velocities were measured from November 2015 to December 2016 at 12 GPS stations deployed from the ice front to 430 km upstream. The flow-parallel velocity anomaly at each station, relative to the annual mean, was small during early austral summer (November–January), negative during February–April, and positive during austral winter (May–September). The maximum velocity anomaly reached several metres per year at most stations. We used a 2-D ice-sheet model of the RIS and its grounded tributaries to explore the seasonal response of the ice sheet to time-varying basal melt rates. We find that melt-rate response to changes in summer upper-ocean heating near the ice front will affect the future flow of RIS and its tributary glaciers. However, modelled seasonal flow variations from increased summer basal melting near the ice front are much smaller than observed, suggesting that other as-yet-unidentified seasonal processes are currently dominant.
Publisher: American Geophysical Union (AGU)
Date: 07-2019
DOI: 10.1029/2018JC014683
Publisher: American Geophysical Union (AGU)
Date: 07-2014
DOI: 10.1002/2014JC009792
Publisher: American Geophysical Union (AGU)
Date: 22-02-2014
DOI: 10.1002/2013GL059153
Location: United States of America
Location: United States of America
Start Date: 2014
End Date: 2019
Funder: Directorate for Geosciences
View Funded ActivityStart Date: 2017
End Date: 2020
Funder: Directorate for Geosciences
View Funded ActivityStart Date: 2015
End Date: 2019
Funder: Directorate for Geosciences
View Funded ActivityStart Date: 2012
End Date: 2016
Funder: Directorate for Geosciences
View Funded ActivityStart Date: 2012
End Date: 2014
Funder: Directorate for Geosciences
View Funded Activity