@article {337,
	title = {Non-linear glacier response to calving events, Jakobshavn Isbr{\ae}, Greenland},
	journal = {Journal of Glaciology},
	volume = {65},
	year = {2019},
	pages = {39{\textendash}54},
	abstract = {Jakobshavn Isbr{\ae}, a tidewater glacier that produces some of Greenland{\textquoteright}s largest icebergs and highest speeds, reached record-high flow rates in 2012 (Joughin and others, 2014). We use terrestrial radar interferometric observations from August 2012 to characterize the events that led to record-high flow. We find that the highest speeds occurred in response to a small calving retreat, while several larger calving events produced negligible changes in glacier speed. This non-linear response to calving events suggests the terminus was close to flotation and therefore highly sensitive to terminus position. Our observations indicate that a glacier{\textquoteright}s response to calving is a consequence of two competing feedbacks: (1) an increase in strain rates that leads to dynamic thinning and faster flow, thereby promoting destabilization, and (2) an increase in flow rates that advects thick ice toward the terminus and promotes restabilization. The competition between these feedbacks depends on temporal and spatial variations in the glacier{\textquoteright}s proximity to flotation. This study highlights the importance of dynamic thinning and advective processes on tidewater glacier stability, and further suggests the latter may be limiting the current retreat due to the thick ice that occupies Jakobshavn Isbr{\ae}{\textquoteright}s retrograde bed.},
	keywords = {calving, dynamic thinning, Jakobshavn Isbr{\ae}, terrestrial radar interferometry, tidewater glaciers},
	issn = {00221430},
	doi = {10.1017/jog.2018.90},
	author = {Cassotto, Ryan and Fahnestock, Mark and Amundson, Jason M. and Truffer, Martin and Boettcher, Margaret S. and De La Pe{\~n}a, Santiago and Howat, Ian}
}
@article {apr,
	title = {Asynchronous behavior of outlet glaciers feeding Godth{\aa}bsfjord (Nuup Kangerlua) and the triggering of Narsap Sermia{\textquoteright}s retreat in SW Greenland},
	journal = {J. Glaciol.},
	volume = {63},
	year = {2017},
	month = {apr},
	pages = {288{\textendash}308},
	abstract = {We assess ice loss and velocity changes between 1985 and 2014 of three tidewater and five-land terminating glaciers in Godth{\aa}bsfjord (Nuup Kangerlua), Greenland. Glacier thinning accounted for 43.8 {\textpm} 0.2 km 3 of ice loss, equivalent to 0.10 mm eustatic sea-level rise. An additional 3.5 {\textpm} 0.3 km 3 was lost to the calving retreats of Kangiata Nunaata Sermia (KNS) and Narsap Sermia (NS), two tidewater glaciers that exhibited asynchronous behavior over the study period. KNS has retreated 22 km from its Little Ice Age (LIA) maximum (1761 AD), of which 0.8 km since 1985. KNS has stabilized in shallow water, but seasonally advects a 2 km long floating tongue. In contrast, NS began retreating from its LIA moraine in 2004{\textendash}06 (0.6 km), re-stabilized, then retreated 3.3 km during 2010{\textendash}14 into an over-deepened basin. Velocities at KNS ranged 5{\textendash}6 km a -1 , while at NS they increased from 1.5 to 5.5 km a -1 between 2004 and 2014. We present comprehensive analyses of glacier thinning, runoff, surface mass balance, ocean conditions, submarine melting, bed topography, ice m{\'e}lange and conclude that the 2010{\textendash}14 NS retreat was triggered by a combination of factors but primarily by an increase in submarine melting.},
	keywords = {glacier calving, glacier discharge, glacier mass balance, ice/atmosphere interactions, ice/ocean interactions, tidewater glaciers},
	issn = {0022-1430},
	doi = {10.1017/jog.2016.138},
	author = {Motyka, Roman J. and Cassotto, Ryan and Truffer, Martin and Kjeldsen, Kristian K. and Van As, Dirk and Korsgaard, Niels J. and Fahnestock, Mark and Howat, Ian and Langen, Peter L. and Mortensen, John and Lennert, Kunuk and Rysgaard, S{\o}ren}
}
@article {Joughin2008a,
	title = {{Ice-front variation and tidewater behavior on Helheim and Kangerdlugssuaq Glaciers, Greenland}},
	journal = {Journal of Geophysical Research: Earth Surface},
	volume = {113},
	number = {1},
	year = {2008},
	month = {jan},
	pages = {1{\textendash}11},
	abstract = {We used satellite images to examine the calving behavior ofHelheim and Kangerdlugssuaq Glaciers, Greenland, from 2001 to 2006, a period in which they retreated and speed up. These data show that many large iceberge-calving episodes coincided with teleseismically detected glacial erthquakes, suggesting that calving-related processes are the source of seismicity. For each of several events for which we hace observations, the ice front calved back to a large, pre-existing rift. These refits form where the ice has thinned to near flotation as the ice front retreats down back side of a bathymetric high, which agrees well with earlier theoretical predictions. In adition to recent retreat in a period of high temperature, analysis of several images shows that Helhaim retreated in the 20th Century during a warmer period and then re-adcanced during a subsequent cooler period. This apparent sensitivity to waming suggests that higher temperatures may promote an initial retread off a bathymetric high that is then sustained by tidewater dynamics as the ice front retreats into depper water. The cycle of frontal advance and retreat in less than a century indicates that tidewater glaciers in Greenland can advance rapidly. Greenland{\textquoteright}s larger resorvoir of inland ice and conditions that favor the formation of ice shelves likely contribute to the rapid rates of advance.},
	isbn = {0148-0227},
	issn = {21699011},
	doi = {10.1029/2007JF000837},
	url = {http://www.agu.org/pubs/crossref/2008/2007JF000837.shtml},
	author = {Joughin, Ian and Howat, Ian and Alley, Richard B. and Ekstrom, Goran and Fahnestock, Mark and Moon, Twila and Nettles, Meredith and Truffer, Martin and Tsai, Victor C.}
}
