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Heterogenous Thinning and Subglacial Lake Activity on Thwaites Glacier, West Antarctica Andrew O
https://doi.org/10.5194/tc-2020-80 Preprint. Discussion started: 9 April 2020 c Author(s) 2020. CC BY 4.0 License. Brief Communication: Heterogenous thinning and subglacial lake activity on Thwaites Glacier, West Antarctica Andrew O. Hoffman1, Knut Christianson1, Daniel Shapero2, Benjamin E. Smith2, Ian Joughin2 1Department of Earth and Space Sciences, University of Washington, Seattle, 98115, United States of America 5 2Applied Physics Laboratory, University of Washington, 98115, United States of America Correspondence to: Andrew O. Hoffman ([email protected]) Abstract. A system of subglacial laKes drained on Thwaites Glacier from 2012-2014. To improve coverage for subsequent drainage events, we extended the elevation and ice velocity time series on Thwaites Glacier through austral winter 2019. These new observations document a second drainage cycle and identified two new laKe systems located in the western tributaries of 10 Thwaites and Haynes Glaciers. In situ and satellite velocity observations show temporary < 3% speed fluctuations associated with laKe drainages. In agreement with previous studies, these observations suggest that active subglacial hydrology has little influence on Thwaites Glacier thinning and retreat on decadal to centennial timescales. 1 Introduction Although subglacial laKes beneath the Antarctic Ice Sheet were first discovered more than 50 years ago (Robin et al., 1969; 15 Oswald and Robin, 1973), they remain one of the most enigmatic components of the subglacial hydrology system. Initially identified in ice-penetrating radar data as flat, bright specular reflectors (Oswald and Robin, 1973; Carter et al., 2007) subglacial laKes were thought to be relatively steady-state features of the basal hydrology system with little impact on the dynamics of the overlying ice on multi-year timescales. -
The Triggers of the Disaggregation of Voyeykov Ice Shelf (2007), Wilkes Land, East Antarctica, and Its Subsequent Evolution
Journal of Glaciology The triggers of the disaggregation of Voyeykov Ice Shelf (2007), Wilkes Land, East Antarctica, and its subsequent evolution Article Jennifer F. Arthur1 , Chris R. Stokes1, Stewart S. R. Jamieson1, 1 2 3 Cite this article: Arthur JF, Stokes CR, Bertie W. J. Miles , J. Rachel Carr and Amber A. Leeson Jamieson SSR, Miles BWJ, Carr JR, Leeson AA (2021). The triggers of the disaggregation of 1Department of Geography, Durham University, Durham, DH1 3LE, UK; 2School of Geography, Politics and Voyeykov Ice Shelf (2007), Wilkes Land, East Sociology, Newcastle University, Newcastle-upon-Tyne, NE1 7RU, UK and 3Lancaster Environment Centre/Data Antarctica, and its subsequent evolution. Science Institute, Lancaster University, Bailrigg, Lancaster, LA1 4YW, UK Journal of Glaciology 1–19. https://doi.org/ 10.1017/jog.2021.45 Abstract Received: 15 September 2020 The weakening and/or removal of floating ice shelves in Antarctica can induce inland ice flow Revised: 31 March 2021 Accepted: 1 April 2021 acceleration. Numerical modelling suggests these processes will play an important role in Antarctica’s future sea-level contribution, but our understanding of the mechanisms that lead Keywords: to ice tongue/shelf collapse is incomplete and largely based on observations from the Ice/atmosphere interactions; ice/ocean Antarctic Peninsula and West Antarctica. Here, we use remote sensing of structural glaciology interactions; ice-shelf break-up; melt-surface; sea-ice/ice-shelf interactions and ice velocity from 2001 to 2020 and analyse potential ocean-climate forcings to identify mechanisms that triggered the rapid disintegration of ∼2445 km2 of ice mélange and part of Author for correspondence: the Voyeykov Ice Shelf in Wilkes Land, East Antarctica between 27 March and 28 May 2007. -
NASA Astronaut Describes Close Call Following Failed Launch 16 October 2018, by Marcia Dunn
NASA astronaut describes close call following failed launch 16 October 2018, by Marcia Dunn It was the first aborted launch for the Russians in 35 years and only the third in history. Like each one before, the rocket's safety system kept the crew alive. Hague—the first American to experience a launch abort like this—communicated in Russian throughout the more than half-hour ordeal. "All of my instincts and reflexes inside the capsule are to speak Russian," said Hague, who had two years of training in Russia. "We knew that if we wanted to be successful, we In this frame from video from NASA TV, NASA astronaut needed to stay calm and we needed to execute the Nick Hague, who survived the Oct. 11, 2018, failed procedures in front of us as smoothly and efficiently launch and emergency landing, speaks Tuesday, Oct. as we could," Hague told The Associated Press 16, 2018, from the NASA Johnson Space Center in from Houston. Houston. Hague and Russian Alexei Ovchinin were two minutes into their flight last Thursday from Kazakhstan to the International Space Station when the Soyuz rocket The astronauts experienced a few moments of failed. (NASA TV via AP) weightlessness after their Soyuz capsule catapulted away from the rocket. Hague, making his first launch, saw the curvature of Earth and the blackness of space. The NASA astronaut who survived last week's failed launch and emergency landing knew he Between the abort and touchdown, Hague looked needed to stay calm. out the window to make sure the capsule's systems were operating properly and to check their landing. -
Tidal Modulation of Antarctic Ice Shelf Melting Ole Richter1,2, David E
Tidal Modulation of Antarctic Ice Shelf Melting Ole Richter1,2, David E. Gwyther1, Matt A. King2, and Benjamin K. Galton-Fenzi3 1Institute for Marine and Antarctic Studies, University of Tasmania, Private Bag 129, Hobart, TAS, 7001, Australia. 2Geography & Spatial Sciences, School of Technology, Environments and Design, University of Tasmania, Hobart, TAS, 7001, Australia. 3Australian Antarctic Division, Kingston, TAS, 7050, Australia. Correspondence: Ole Richter ([email protected]) This is a non-peer reviewed preprint submitted to EarthArXiv. This preprint has also been submitted to The Cryosphere for peer review. 1 Abstract. Tides influence basal melting of individual Antarctic ice shelves, but their net impact on Antarctic-wide ice-ocean interaction has yet to be constrained. Here we quantify the impact of tides on ice shelf melting and the continental shelf seas 5 by means of a 4 km resolution circum-Antarctic ocean model. Activating tides in the model increases the total basal mass loss by 57 Gt/yr (4 %), while decreasing continental shelf temperatures by 0.04 ◦C, indicating a slightly more efficient conversion of ocean heat into ice shelf melting. Regional variations can be larger, with melt rate modulations exceeding 500 % and temperatures changing by more than 0.5 ◦C, highlighting the importance of capturing tides for robust modelling of glacier systems and coastal oceans. Tide-induced changes around the Antarctic Peninsula have a dipolar distribution with decreased 10 ocean temperatures and reduced melting towards the Bellingshausen Sea and warming along the continental shelf break on the Weddell Sea side. This warming extends under the Ronne Ice Shelf, which also features one of the highest increases in area-averaged basal melting (150 %) when tides are included. -
IS Leader Linked to Beheadings Killed
06 TUESDAY, DECEMBER 4, 2018 world Dutchman, 69, IS leader linked to loses legal bid to be beheadings killed 20 years younger US-led coalition kills IS leader linked to the beheading of an American aid worker Abu al-Umarayn was accused• of involvement in the November Emile Ratelband, 69, answers journalists’ questions in Amsterdam, following 2014 beheading of the court’s ruling regarding his legal bid to slash 20 years off his age. Peter Kassig viously said he felt discrimi- The Hague, Netherlands nated against because of his AFP | Beirut, Lebanon advanced years, adding that Dutch court yesterday while he did not need dating he US-led coalition A slapped down an attempt apps, the custom of giving his against the Islamic State by a self-described “young age to a prospective lover was Tgroup said yesterday it god” just shy of his 70th birth- cramping his style. killed a senior jihadist involved day to slash his age by 20 years “I am a young god, I can have in the executions of an Ameri- to enhance his prospects in life all the girls that I want, but not can aid worker and other West- and love. after I tell them that I am 69,” ern hostages. In an unprecedented case, he recently said. Abu al-Umarayn was accused the Arnhem District Court told “I feel young, I am in great of involvement in the November “positivity guru” Emile Ratel- shape and I want this to be 2014 beheading of Peter Kassig, band it will not adhere to his legally recognised because I a former US ranger who was request to shift his birthdate feel abused, aggrieved and dis- doing volunteer humanitarian two decades later to March criminated against because of work when captured in 2013. -
Ice News Bulletin of the International
ISSN 0019–1043 Ice News Bulletin of the International Glaciological Society Number 154 3rd Issue 2010 Contents 2 From the Editor 25 Staff changes 3 Recent work 25 New Chair for the Awards Committee 3 Australia 26 Report from the IGS conference on Snow, 3 Ice cores Ice and Humanity in a Changing Climate, 4 Ice sheets, glaciers and icebergs Sapporo, Japan, 21–25 June 2010 5 Sea ice and glacimarine processes 31 Report from the British Branch Meeting, 6 Large-scale processes Aberystwyth 7 Remote sensing 32 Meetings of other societies 8 Numerical modelling 32 Workshop of Glacial Erosion 9 Ecology within glacial systems Modelling 10 Geosciences and glacial geology 33 Northwest Glaciologists’ Meeting 11 International Glaciological Society 35 UKPN Circumpolar Remote Sensing 11 Journal of Glaciology Workshop 14 Annals of Glaciology 51(56) 35 Notes from the production team 15 Annals of Glaciology 52(57) 36 San Diego symposium, 2nd circular 16 Annals of Glaciology 52(58) 44 News 18 Annals of Glaciology 52(59) 44 Obituary: Keith Echelmeyer 19 Annual General Meeting 2010 46 70th birthday celebration for 23 Books received Sigfús Johnsen 24 Award of the Richardson Medal to 48 Glaciological diary Jo Jacka 54 New members Cover picture: Spiral icicle extruded from the tubular steel frame of a jungle gym in Moscow, November 2010. Photo: Alexander Nevzorov. Scanning electron micrograph of the ice crystal used in headings by kind permission of William P. Wergin, Agricultural Research Service, US Department of Agriculture EXCLUSION CLAUSE. While care is taken to provide accurate accounts and information in this Newsletter, neither the editor nor the International Glaciological Society undertakes any liability for omissions or errors. -
Article Is Available On- Mand of Charles Wilkes, USN
The Cryosphere, 15, 663–676, 2021 https://doi.org/10.5194/tc-15-663-2021 © Author(s) 2021. This work is distributed under the Creative Commons Attribution 4.0 License. Recent acceleration of Denman Glacier (1972–2017), East Antarctica, driven by grounding line retreat and changes in ice tongue configuration Bertie W. J. Miles1, Jim R. Jordan2, Chris R. Stokes1, Stewart S. R. Jamieson1, G. Hilmar Gudmundsson2, and Adrian Jenkins2 1Department of Geography, Durham University, Durham, DH1 3LE, UK 2Department of Geography and Environmental Sciences, Northumbria University, Newcastle upon Tyne, NE1 8ST, UK Correspondence: Bertie W. J. Miles ([email protected]) Received: 16 June 2020 – Discussion started: 6 July 2020 Revised: 9 November 2020 – Accepted: 10 December 2020 – Published: 11 February 2021 Abstract. After Totten, Denman Glacier is the largest con- 1 Introduction tributor to sea level rise in East Antarctica. Denman’s catch- ment contains an ice volume equivalent to 1.5 m of global sea Over the past 2 decades, outlet glaciers along the coast- level and sits in the Aurora Subglacial Basin (ASB). Geolog- line of Wilkes Land, East Antarctica, have been thinning ical evidence of this basin’s sensitivity to past warm periods, (Pritchard et al., 2009; Flament and Remy, 2012; Helm et combined with recent observations showing that Denman’s al., 2014; Schröder et al., 2019), losing mass (King et al., ice speed is accelerating and its grounding line is retreating 2012; Gardner et al., 2018; Shen et al., 2018; Rignot et al., along a retrograde slope, has raised the prospect that its con- 2019) and retreating (Miles et al., 2013, 2016). -
US-Russian Crew Blasts Off to International Space Station 14 March 2019, by Vladimir Isachenkov and Dmitry Lovetsky
US-Russian crew blasts off to International Space Station 14 March 2019, by Vladimir Isachenkov And Dmitry Lovetsky On Oct. 11, a Soyuz that Hague and Ovchinin were riding in failed two minutes into its flight, activating a rescue system that allowed their capsule to land safely. That accident was the first aborted crew launch for the Russian space program since 1983, when two Soviet cosmonauts safely jettisoned after a launch pad explosion. NASA Administrator Jim Bridenstine congratulated the crew on a successful launch. "So proud of Nick Hague for persevering through last October's launch that didn't go as planned," he tweeted. Speaking at a pre-launch news conference at Baikonur, the crew said they trusted the rocket and U.S. astronauts Christina Hammock Koch, centre, Nick fully believed in the success of their mission. Hague, above, and Russian cosmonaut Alexey Ovchinin, crew members of the mission to the International Space Station, ISS, wave as they board to the rocket prior the launch of Soyuz-FG rocket at the Russian leased Baikonur cosmodrome, Kazakhstan, Thursday, March 14, 2019. (AP Photo/Kyrill Kudryavtsev, Pool) A Russian-American crew of three blasted off to the International Space Station early Friday, making a second attempt to reach the outpost after October's aborted launch. A Russian Soyuz rocket carrying NASA astronauts U.S. astronauts Christina Hammock Koch, left, Nick Nick Hague and Christina Koch along with Hague, right, and Russian cosmonaut Alexey Ovchinin, Roscosmos' Alexei Ovchinin lifted off as planned members of the main crew to the International Space from the Baikonur cosmodrome in Kazakhstan at Station (ISS), pose near a bus prior to the launch of the 12:14 a.m. -
Noaa 4860 DS1.Pdf
PROPOSED ACTION: Issuance of an Incidental Harassment Authorization to the National Science Foundation and Antarctic Support Contract to Take Marine Mammals by Harassment Incidental to a Low-Energy Marine Geophysical Survey in the Dumont d’Urville Sea off the Coast of East Antarctica, January to March 2014. TYPE OF STATEMENT: Environmental Assessment LEAD AGENCY: U.S. Department of Commerce, National Oceanic and Atmospheric Administration National Marine Fisheries Service RESPONSIBLE OFFICIAL: Donna S. Wieting, Director, Office of Protected Resources, National Marine Fisheries Service FOR FURTHER INFORMATION: Howard Goldstein National Marine Fisheries Service Office of Protected Resources, Permits and Conservation Division 1315 East West Highway Silver Spring, MD 20910 301-427-8401 LOCATION: Selected regions of the Dumont d’Urville Sea in International Waters of the Southern Ocean off the coast of East Antarctica (Approximately 64º South, between 95 and 135º East, and 65º South, between 140 to 165º East) ABSTRACT: This Environmental Assessment analyzes the environmental impacts of the National Marine Fisheries Service, Office of Protected Resources, Permits and Conservation Division’s proposal to issue an Incidental Harassment Authorization to the National Science Foundation and Antarctic Support Contract for the taking, by Level B harassment, of small numbers of marine mammals, incidental to conducting a low-energy marine geophysical survey in the Dumont d’Urville Sea, January to March 2014. CONTENTS List of Abbreviations or Acronyms -
USMA Class of 2020: ‟With Vision We Lead” in Their Own Words Compiled by Eric S
JUNE 4, 2020 1 WWW.WESTPOINT.EDU THE J UNE 4, 2020 VOL. 77, NO. 21 OINTER IEW® DUTY, HONOR, COUNTRY PSERVING THE U.S. MILITARY ACADEMY AND THE COMMUNITY V OF WEST POINT ® SEE INSIDE FOR MORE COVID-19 INFORMATION POINTER VIEW INSIDE & ONLINE WWW . WESTPOINT . EDU / NEWS WWW . POINTERVIEW . COM USMA PAO continues to provide Army leadership visits USMA comprehensive resources across the West Point community through U.S. Military Academy leadership briefed Chief of Staff of the Army Gen. James C. McConville and Sgt. Maj. of the the West Point Coronavirus Army Michael A. Grinston (above) on the preparations West Point has made to operate in a COVID-19 environment webpage at www.westpoint.edu/ and welcome back the Corps of Cadets during their visit to the academy Wednesday. McConville and Grinston also visited the COVID-19 ward at Keller Army Community Hospital and ate a socially distanced lunch in the Cadet Mess coronavirus, and it has released Hall (below) with members of the Class of 2020. Photos by Tarnish Pride/USMA PAO external messages on USMA social media platforms. For more information, contact the West Point Public Affairs Offi ce at [email protected]. See page 2 for a story on the Class of 2020 preparing for graduation after its return to West Point. See pages 4-7, 12-13 for a story on West Point’s Women of the Long Gray Line. See pages 8-11 for Class of 2020 members’ narratives on their West Point experience. 2 JUNE 4, 2020 NEWS & FEATURES POINTER VIEW Class of 2020 settling in, preparing for graduation after return to West Point By Brandon O’Connor They also have to return equipment, receive PV Assistant Editor their orders and pack up their rooms in the barracks so they can move to their Basic Offi cer After a fi ve-day process, the members of Leaders Course locations and then eventually the U.S. -
Expedition 59
INTERNATIONAL SPACE STATION EXPEDITION 59 Soyuz MS-11 Launch: December 3, 2018 Soyuz MS-12 Launch: March, 2019 Landing: June, 2019 Landing: September, 2019 ANN McCLAIN (NASA) CHRISTINA KOCH (NASA) Flight Engineer Flight Engineer Born: Spokane, Washington Born: Grand Rapids, Michigan Interests: Weightlifting, rugby, golf, Interests: Backpacking, rock biking, fitness training and running climbing, paddling and sailing Spaceflights: First flight Spaceflights: First Flight Bio: https://go.nasa.gov/2s8ryrB Bio: https://go.nasa.gov/2QCRHbX Twitter: @AstroAnnimal Twitter: @Astro_Christina DAVID SAINT-JACQUES (CSA) NICK HAGUE (NASA) Flight Engineer Flight Engineer Born: Saint-Lambert, Quebec Born: Belleville, Kansas Interests: Mountaineering, cycling, Interests: Exercise, flying, snow skiing skiing and sailing and scuba Spaceflights: First flight Spaceflights: Soyuz MS-10 Bio: https://go.nasa.gov/2VBcqAu Bio: https://go.nasa.gov/2Qz3qZ1 Twitter: @Astro_DavidS Twitter: @AstroHague OLEG KONONENKO (Roscosmos) ALEXEY OVCHININ (Roscosmos) Commander Flight Engineer Born: Türkmenabat, Turkmenistan Born: Rybinsk, Russia Spaceflights: Exp. 17, 30/31, 44/45 Spaceflights: Exp 47/48 Bio: https://go.nasa.gov/2QviZ3S Bio: https://go.nasa.gov/2QAQBgu Twitter: Text EXPEDITION Expedition 59 began in March 2019 and ends in June 2019. This expedition will include research investigations and technology demonstrations not possible on Earth to advance scientific knowledge of 59 Earth, space, physical and biological sciences. During Expedition 59, researchers will use tissue chips to study changes in the human body caused by microgravity, conduct research on regolith simulants in the Hermes research facility, test free-flying robots inside the station and study the complex dynamics of the Earth’s atmospheric carbon cycle using the Orbiting Carbon Observatory 3 space instrument. -
Individual and Organizational Donors
INDIVIDUAL AND ORGANIZATIONAL Illinois Tool Works Foundation Colliers International The Irving Harris Foundation Community Memorial Foundation DONORS J.R. Albert Foundation Crain's Chicago Business Jones Lang LaSalle Patrick and Anna M. Cudahy Fund $100,000 and above The Joyce Foundation Cushman & Wakefield of Illinois, Inc. Anonymous (8) Julie and Brian Simmons Foundation The Damico Family Foundation The Aidmatrix Foundation Knight Family Foundation Mr. Floyd E. Dillman and Dr. Amy Weiler Bank of America Russell and Josephine Kott DLA Piper LLP (US) Charter One Memorial Charitable Trust Eagle Seven, LLC The Chicago Community Trust Henrietta Lange Burk Fund The Earl and Brenda Shapiro Foundation Feeding America Levenfeld Pearlstein, LLC Eastdil Secured Daniel Haerther Living Trust Chicago and NW Mazda Dealers C. J. Eaton Hillshire Brands Foundation Mr. Clyde S. McGregor and Edelstein Foundation JPMorgan Chase Ms. LeAnn Pedersen Pope Eli and Dina Field Family Foundation Mr. Michael L. Keiser and Mrs. Rosalind Keiser Elizabeth Morse Genius Charitable Trust Mr. and Mrs. Eugene F. Fama Kraft Foods Foundation Mr. Saumya Nandi and Ms. Martha Delgado Mr. and Mrs. James Ferry, III Mr. Irving F. Lauf, Jr. Mr. and Mrs. David J. Neithercut Fortune Brands, Inc. Ann and Robert H. Lurie Foundation Dr. Tim D. Noel and Mrs. Joni L. Noel Franklin Philanthropic Foundation McDonald's Corporation Ms. Abby H. Ohl and Mr. Arthur H. Ellis Garvey's Office Products Polk Bros. Foundation The John C. & Carolyn Noonan GE Foundation J.B. and M.K. Pritzker Family Foundation Parmer Private Foundation General Iron Industries Charitable Foundation The Retirement Research Foundation Ms. Laura S.