00570nas a2200145 4500008004100000245007400041210006900115100002900184700002300213700002100236700001700257700002100274700002200295856010700317 2015 eng d00aSubglacial discharge at tidewater glaciers revealed by seismic tremor0 aSubglacial discharge at tidewater glaciers revealed by seismic t1 aBartholomaus, Timothy, C1 aAmundson, Jason, M1 aWalter, Jacob, I1 aO'Neel, Shad1 aWest, Michael, E1 aLarsen, Chris, F. uhttps://glaciers.gi.alaska.edu/content/subglacial-discharge-tidewater-glaciers-revealed-seismic-tremor00536nas a2200169 4500008004100000245005500041210005500096300001600151490000700167100002200174700001500196700001500211700001400226700001600240700001600256856009400272 2015 eng d00aSurface melt dominates Alaska glacier mass balance0 aSurface melt dominates Alaska glacier mass balance a5902–59080 v421 aLarsen, Chris, F.1 aBurgess, E1 aArendt, AA1 aO'Neel, S1 aJohnson, AJ1 aKienholz, C uhttps://glaciers.gi.alaska.edu/content/surface-melt-dominates-alaska-glacier-mass-balance00560nas a2200157 4500008004100000245007800041210006900119300001200188490000700200100001500207700001500222700002200237700001500259700001300274856011500287 2014 eng d00aAlaska National Park glaciers: what do they tell us about climate change?0 aAlaska National Park glaciers what do they tell us about climate a18–250 v121 aLoso, M.G.1 aArendt, A.1 aLarsen, Chris, F.1 aMurphy, N.1 aRich, J. uhttps://glaciers.gi.alaska.edu/content/alaska-national-park-glaciers-what-do-they-tell-us-about-climate-change01895nas a2200205 4500008004100000022001400041245008500055210006900140300001400209520127900223653001101502653001201513653002101525653001401546653001801560100001901578700002901597700002201626856004101648 2013 eng d a2169-935600aActive tectonics of the St. Elias orogen, Alaska, observed with GPS measurements0 aActive tectonics of the St Elias orogen Alaska observed with GPS an/a–n/a3 aWe use data from campaign and continuous GPS sites in southeast and south central Alaska to constrain a regional tectonic block model for the St. Elias orogen. Active tectonic deformation in the orogen is dominated by the effects of the collision of the Yakutat block with southern Alaska. Our results indicate that 37 mm/yr of convergence is accommodated along a relatively narrow belt of N-NW dipping thrust faults in the eastern half of the orogen, with the present-day deformation front running through Icy Bay and beneath the Malaspina Glacier. Near the Bering Glacier, the collisional thrust fault regime transitions into a broad, northwest dipping décollement as the Yakutat block basement begins to subduct beneath the counterclockwise rotating Elias block. The location of this transition aligns with the Gulf of Alaska shear zone, implying that the Pacific plate is fragmenting in response to the Yakutat collision. Our model indicates that the Bering Glacier region is undergoing internal deformation and could correspond to the final stage of offscraping and accretion of sediments from the Yakutat block prior to subduction. Predicted block motions at the western edge of the orogen suggest that the crust is laterally escaping along the Aleutian fore arc.10aAlaska10ageodesy10aSt. Elias orogen10atectonics10aYakutat block1 aElliott, Julie1 aFreymueller, Jeffrey, T.1 aLarsen, Chris, F. uhttp://dx.doi.org/10.1002/jgrb.5034100491nas a2200145 4500008004100000022001400041245006500055210006400120300001200184490000800196100003000204700002200234700001800256856007100274 2013 eng d a0012-821X00aDoes calving matter? Evidence for significant submarine melt0 aDoes calving matter Evidence for significant submarine melt a21 - 300 v3801 aBartholomaus, Timothy, C.1 aLarsen, Chris, F.1 aOʼNeel, Shad uhttp://www.sciencedirect.com/science/article/pii/S0012821X1300440800359nas a2200121 4500008004100000245004000041210004000081490000600121100002200127700002500149700002200174856004100196 2013 eng d00aFlow velocities of Alaskan glaciers0 aFlow velocities of Alaskan glaciers0 v41 aBurgess, Evan, W.1 aForster, Richard, R.1 aLarsen, Chris, F. uhttp://dx.doi.org/10.1038/ncomms314601582nas a2200241 4500008004100000022001400041245007600055210006900131300001400200520091200214653001101126653001901137653001501156653001701171653001001188653001401198100001701212700001701229700002201246700001201268700001701280856004301297 2013 eng d a1944-800700aLow-frequency radar sounding of temperate ice masses in Southern Alaska0 aLowfrequency radar sounding of temperate ice masses in Southern an/a–n/a3 aWe present the Warm Ice Sounding Explorer (WISE), a low-frequency (2.5 MHz) radar for the sounding of temperate ice. WISE deployment in southern Alaska in 2008 and 2012 provides comprehensive measurements of glacier thickness, reveals deep valleys beneath glaciers and the full extent of zones grounded below sea level. The east branch of Columbia Glacier is deeper that its main branch and remains below sea level 20 km farther inland. Ice is 1000 m deep on Tazlina Glacier. On Bering glacier, two sills separate three deep bed depressions (>1200 m) that coincide with the dynamic balance lines during surges. The piedmont lobe of Malaspina Glacier and the lower reaches of Hubbard Glacier are entirely grounded below sea level 40 and 10 km, respectively, from their termini. Knowledge of ice thickness in these regions helps better understand their glacier dynamics, mass balance, and impact on sea level.10aAlaska10abed topography10aglaciology10amass balance10aradar10athickness1 aRignot, Eric1 aMouginot, J.1 aLarsen, Chris, F.1 aGim, Y.1 aKirchner, D. uhttp://dx.doi.org/10.1002/2013GL05745200668nas a2200157 4500008004100000245013100041210006900172300001400241490000700255100002300262700002200285700002200307700002400329700002100353856013600374 2013 eng d00aMass balance in the Glacier Bay area of Alaska, USA, and British Columbia, Canada, 1995–2011, using airborne laser altimetry0 aMass balance in the Glacier Bay area of Alaska USA and British C a632–6480 v591 aJohnson, Austin, J1 aLarsen, Chris, F.1 aMurphy, Nathaniel1 aArendt, Anthony, A.1 aZirnheld, S, Lee uhttps://glaciers.gi.alaska.edu/content/mass-balance-glacier-bay-area-alaska-usa-and-british-columbia-canada-1995%E2%80%932011-using01821nas a2200157 4500008004100000245008000041210006900121300001200190490000700202520128600209100001801495700002501513700002201538700001901560856008401579 2013 eng d00aThe propagation of a surge front on Bering Glacier, Alaska, 2001–20110 apropagation of a surge front on Bering Glacier Alaska 2001821120 a221-2280 v543 aBering Glacier, Alaska, USA, has a ∼20 year surge cycle, with its most recent surge reaching the terminus in 2011. To study this most recent activity a time series of ice velocity maps was produced by applying optical feature-tracking methods to Landsat-7 ETM+ imagery spanning 2001–11. The velocity maps show a yearly increase in ice surface velocity associated with the down-glacier movement of a surge front. In 2008/09 the maximum ice surface velocity was 1.5 ± 0.017 km a–1 in the mid-ablation zone, which decreased to 1.2 ± 0.015 km a–1 in 2009/10 in the lower ablation zone, and then increased to nearly 4.4 ± 0.03 km a–1 in summer 2011 when the surge front reached the glacier terminus. The surge front propagated down-glacier as a kinematic wave at an average rate of 4.4 ± 2.0 km a–1 between September 2002 and April 2009, then accelerated to 13.9 ± 2.0 km a–1 as it entered the piedmont lobe between April 2009 and September 2010. The wave seems to have initiated near the confluence of Bering Glacier and Bagley Ice Valley as early as 2001, and the surge was triggered in 2008 further down-glacier in the mid-ablation zone after the wave passed an ice reservoir area.1 aTurrin, James1 aForster, Richard, R.1 aLarsen, Chris, F.1 aSauber, Jeanne uhttp://www.ingentaconnect.com/content/igsoc/agl/2013/00000054/00000063/art0002401577nas a2200205 4500008004100000022001400041245007100055210006900126520095700195653001101152653001701163653002201180653002001202653002601222653001101248100002201259700002201281700002501303856004301328 2013 eng d a1944-800700aSummer melt regulates winter glacier flow speeds throughout Alaska0 aSummer melt regulates winter glacier flow speeds throughout Alas3 aPredicting how climate change will affect glacier and ice sheet flow speeds remains a large hurdle towards accurate sea level rise forecasting. Increases in surface melt rates are known to accelerate glacier flow in summer, whereas in winter, flow speeds are believed to be relatively invariant. Here we show that wintertime flow speeds on nearly all major glaciers throughout Alaska are not only variable but are inversely related to melt from preceding summers. For each additional meter of summertime melt, we observe an 11% decrease in wintertime velocity on glaciers of all sizes, geometries, climates and bed types. This dynamic occurs because inter-annual differences in summertime melt affect how much water is retained in the sub-glacial system during winter. The ubiquity of the dynamic indicates it occurs globally on glaciers and ice sheets not frozen to their beds and thus constitutes a new mechanism affecting sea level rise projections.10aAlaska10aIce Dynamics10aMountain Glaciers10aOffset Tracking10aSub-Glacial Hydrology10aWinter1 aBurgess, Evan, W.1 aLarsen, Chris, F.1 aForster, Richard, R. uhttp://dx.doi.org/10.1002/2013GL05822800457nas a2200145 4500008004100000245006300041210006300104300001100167490000800178100003000186700002200216700001800238700001200256856004300268 2012 eng d00aCalving seismicity from iceberg–sea surface interactions0 aCalving seismicity from iceberg–sea surface interactions aF040290 v1171 aBartholomaus, Timothy, C.1 aLarsen, Chris, F.1 aOʼNeel, Shad1 aWest, M uhttps://glaciers.gi.alaska.edu/node/8000666nas a2200217 4500008004100000245010600041210006900147300001100216490000800227100001800235700001300253700001100266700001400277700002900291700002200320700001200342700001600354700001300370700002200383856004300405 2012 eng d00aGravity and uplift rates observed in southeast Alaska and their comparison with GIA model predictions0 aGravity and uplift rates observed in southeast Alaska and their aB014010 v1171 aSato, Tatsuru1 aMiura, S1 aSun, W1 aSugano, T1 aFreymueller, Jeffrey, T.1 aLarsen, Chris, F.1 aOhta, Y1 aFujimoto, H1 aInazu, D1 aMotyka, Roman, J. uhttps://glaciers.gi.alaska.edu/node/5900454nas a2200145 4500008004100000245006100041210005900102300001600161490000600177100002200183700002500205700002200230700001300252856004300265 2012 eng d00aSurge dynamics on Bering Glacier, Alaska, in 2008–20110 aSurge dynamics on Bering Glacier Alaska in 2008–2011 a1181–12040 v61 aBurgess, Evan, W.1 aForster, Richard, R.1 aLarsen, Chris, F.1 aBraun, M uhttps://glaciers.gi.alaska.edu/node/7900629nas a2200193 4500008004100000245011900041210006900160300001200229490000800241100001800249700002200267700001300289700001200302700001600314700001100330700002200341700002900363856004300392 2011 eng d00aReevaluation of the viscoelastic and elastic responses to the past and present-day ice changes in Southeast Alaska0 aReevaluation of the viscoelastic and elastic responses to the pa a79–880 v5111 aSato, Tatsuru1 aLarsen, Chris, F.1 aMiura, S1 aOhta, Y1 aFujimoto, H1 aSun, W1 aMotyka, Roman, J.1 aFreymueller, Jeffrey, T. uhttps://glaciers.gi.alaska.edu/node/4601570nas a2200169 4500008004100000245002800041210002800069300001200097490000700109520113600116100001201252700002201264700002001286700001801306700001901324856005701343 2010 eng d00aGlacier microseismicity0 aGlacier microseismicity a319-3220 v383 aWe present a framework for interpreting small glacier seismic events based on data collected near the center of Bering Glacier, Alaska, in spring 2007. We find extremely high microseismicity rates (as many as tens of events per minute) occurring largely within a few kilometers of the receivers. A high-frequency class of seismicity is distinguished by dominant frequencies of 20–35 Hz and impulsive arrivals. A low-frequency class has dominant frequencies of 6–15 Hz, emergent onsets, and longer, more monotonic codas. A bimodal distribution of 160,000 seismic events over two months demonstrates that the classes represent two distinct populations. This is further supported by the presence of hybrid waveforms that contain elements of both event types. The high-low-hybrid paradigm is well established in volcano seismology and is demonstrated by a comparison to earthquakes from Augustine Volcano. We build on these parallels to suggest that fluid-induced resonance is likely responsible for the low-frequency glacier events and that the hybrid glacier events may be caused by the rush of water into newly opening pathways.1 aWest, M1 aLarsen, Chris, F.1 aTruffer, Martin1 aOʼNeel, Shad1 aLeBlanc, Laura uhttp://geology.gsapubs.org/content/38/4/319.abstract00652nas a2200205 4500008004100000245012600041210006900167300001100236490000800247100001100255700001300266700001800279700001400297700002900311700001500340700002200355700001300377700001300390856004300403 2010 eng d00aGravity measurements in southeastern Alaska reveal negative gravity rate of change caused by glacial isostatic adjustment0 aGravity measurements in southeastern Alaska reveal negative grav aB124060 v1151 aSun, W1 aMiura, S1 aSato, Tatsuru1 aSugano, T1 aFreymueller, Jeffrey, T.1 aKaufman, M1 aLarsen, Chris, F.1 aCross, R1 aInazu, D uhttps://glaciers.gi.alaska.edu/node/4500508nas a2200145 4500008004100000245012200041210006900163300001100232490000800243100001800251700002200269700001400291700001400305856004300319 2010 eng d00aIceberg calving as a primary source of regional-scale glacier-generated seismicity in the St. Elias Mountains, Alaska0 aIceberg calving as a primary source of regionalscale glaciergene aF040340 v1151 aOʼNeel, Shad1 aLarsen, Chris, F.1 aRupert, N1 aHansen, R uhttps://glaciers.gi.alaska.edu/node/4800613nas a2200205 4500008004100000245007600041210006900117300001600186490000800202100001400210700001600224700001300240700002300253700001800276700001600294700002200310700001700332700001500349856004300364 2010 eng d00aRecent and future warm extreme events and high-mountain slope stability0 aRecent and future warm extreme events and highmountain slope sta a2435–24590 v3681 aHuggel, C1 aSalzmann, N1 aAllen, S1 aCaplan-Auerbach, J1 aFischer , L1 aHaeberli, W1 aLarsen, Chris, F.1 aSchneider, D1 aWessels, R uhttps://glaciers.gi.alaska.edu/node/5100539nas a2200145 4500008004100000245013100041210006900172300001100241490000800252100001700260700002200277700002900299700002200328856004300350 2010 eng d00aTectonic block motion and glacial isostatic adjustment in southeast Alaska and adjacent Canada constrained by GPS measurements0 aTectonic block motion and glacial isostatic adjustment in southe aB094070 v1151 aElliott, J L1 aLarsen, Chris, F.1 aFreymueller, Jeffrey, T.1 aMotyka, Roman, J. uhttps://glaciers.gi.alaska.edu/node/5300593nas a2200193 4500008004100000245010000041210006900141300001400210490000700224100001300231700001800244700001300262700001200275700001600287700001600303700002200319700001500341856004300356 2009 eng d00aAccurate ocean tide modeling in southeast Alaska and large tidal dissipation around Glacier Bay0 aAccurate ocean tide modeling in southeast Alaska and large tidal a335–3470 v651 aInazu, D1 aSato, Tatsuru1 aMiura, S1 aOhta, Y1 aNakamura, K1 aFujimoto, H1 aLarsen, Chris, F.1 aHiguchi, T uhttps://glaciers.gi.alaska.edu/node/3700595nas a2200205 4500008004100000245006700041210006700108300001200175490000700187100001800194700001300212700001200225700001600237700001100253700002200264700001500286700001600301700002900317856004300346 2008 eng d00aEarth tides observed by gravity and GPS in southeastern Alaska0 aEarth tides observed by gravity and GPS in southeastern Alaska a78–890 v461 aSato, Tatsuru1 aMiura, S1 aOhta, Y1 aFujimoto, H1 aSun, W1 aLarsen, Chris, F.1 aHeavner, M1 aKaufman, AM1 aFreymueller, Jeffrey, T. uhttps://glaciers.gi.alaska.edu/node/1900525nas a2200157 4500008004100000245008900041210006900130300001400199490000700213100002200220700002400242700001800266700001800284700002200302856004300324 2008 eng d00aRecent glacier mass changes in the Gulf of Alaska region from GRACE mascon solutions0 aRecent glacier mass changes in the Gulf of Alaska region from GR a767–7770 v541 aLuthcke, Scott, B1 aArendt, Anthony, A.1 aRowlands, D D1 aMcCarthy, J J1 aLarsen, Chris, F. uhttps://glaciers.gi.alaska.edu/node/2600541nas a2200157 4500008004100000245010600041210006900147300001100216490000800227100002200235700002200257700002400279700002000303700001800323856004200341 2007 eng d00aGlacier changes in southeast Alaska and northwest British Columbia and contribution to sea level rise0 aGlacier changes in southeast Alaska and northwest British Columb aF010070 v1121 aLarsen, Chris, F.1 aMotyka, Roman, J.1 aArendt, Anthony, A.1 aEchelmeyer, K A1 aGeissler, P E uhttps://glaciers.gi.alaska.edu/node/700500nas a2200145 4500008004100000245009100041210006900132300001200201490000600213100002200219700002200241700002900263700002000292856004200312 2007 eng d00aPost Little Ice Age Glacial Rebound in Glacier Bay National Park and Surrounding Areas0 aPost Little Ice Age Glacial Rebound in Glacier Bay National Park a36–410 v61 aMotyka, Roman, J.1 aLarsen, Chris, F.1 aFreymueller, Jeffrey, T.1 aEchelmeyer, K A uhttps://glaciers.gi.alaska.edu/node/6