Quantifying Iceberg Calving Fluxes with Underwater Noise
Total Page:16
File Type:pdf, Size:1020Kb
Load more
Recommended publications
-
100 Magic Water Words
WaterCards.(WebFinal).qxp 6/15/06 8:10 AM Page 1 estuary ocean backwater canal ice flood torrent snowflake iceberg wastewater 10 0 ripple tributary pond aquifer icicle waterfall foam creek igloo cove Water inlet fish ladder snowpack reservoir sleet Words slough shower gulf rivulet salt lake groundwater sea puddle swamp blizzard mist eddy spillway wetland harbor steam Narcissus surf dew white water headwaters tide whirlpool rapids brook 100 Water Words abyssal runoff snow swell vapor EFFECT: Lay 10 cards out blue side up. Ask a participant to mentally select a word and turn the card with the word on it over. You turn all marsh aqueduct river channel saltwater the other cards over and mix them up. Ask the participant to point to the card with his/her water table spray cloud sound haze word on it. You magically tell the word selected. KEY: The second word from the top on the riptide lake glacier fountain spring white side is a code word for a number from one to ten. Here is the code key: Ocean = one (ocean/one) watershed bay stream lock pool Torrent = two (torrent/two) Tributary = three (tributary/three) Foam = four (foam/four) precipitation lagoon wave crest bayou Fish ladder = five (fish ladder/five) Shower = six (shower/six) current trough hail well sluice Sea = seven (sea/seven) Eddy = eight (eddy/eight) Narcissus = nine (Narcissus/nine) salt marsh bog rain breaker deluge Tide = ten (tide/ten) Notice the code word on the card that is first frost downpour fog strait snowstorm turned over. When the second card is selected the chosen word will be the secret number inundation cloudburst effluent wake rainbow from the top. -
An Analytical Model of Iceberg Drift
JULY 2017 W A G N E R E T A L . 1605 An Analytical Model of Iceberg Drift TILL J. W. WAGNER,REBECCA W. DELL, AND IAN EISENMAN University of California, San Diego, La Jolla, California (Manuscript received 2 December 2016, in final form 6 April 2017) ABSTRACT The fate of icebergs in the polar oceans plays an important role in Earth’s climate system, yet a detailed understanding of iceberg dynamics has remained elusive. Here, the central physical processes that determine iceberg motion are investigated. This is done through the development and analysis of an idealized model of iceberg drift. The model is forced with high-resolution surface velocity and temperature data from an obser- vational state estimate. It retains much of the most salient physics, while remaining sufficiently simple to allow insight into the details of how icebergs drift. An analytical solution of the model is derived, which highlights how iceberg drift patterns depend on iceberg size, ocean current velocity, and wind velocity. A long-standing rule of thumb for Arctic icebergs estimates their drift velocity to be 2% of the wind velocity relative to the ocean current. Here, this relationship is derived from first principles, and it is shown that the relationship holds in the limit of small icebergs or strong winds, which applies for typical Arctic icebergs. For the opposite limit of large icebergs (length . 12 km) or weak winds, which applies for typical Antarctic tabular icebergs, it is shown that this relationship is not applicable and icebergs move with the ocean current, unaffected by the wind. -
Calving Flux Estimation from Tsunami Waves
Earth and Planetary Science Letters 515 (2019) 283–290 Contents lists available at ScienceDirect Earth and Planetary Science Letters www.elsevier.com/locate/epsl Calving flux estimation from tsunami waves ∗ Masahiro Minowa a,b, , Evgeny A. Podolskiy c,d, Guillaume Jouvet e, Yvo Weidmann e, Daiki Sakakibara b,c, Shun Tsutaki f, Riccardo Genco g, Shin Sugiyama b a Instituto de Ciencias Físicas y Matemáticas, Universidad Austral de Chile, Valdivia, Chile b Institute of Low Temperature Science, Hokkaido University, Sapporo, Japan c Arctic Research Center, Hokkaido University, Sapporo, Japan d Global Institution for Collaborative Research and Education, Hokkaido University, Sapporo, Japan e Laboratory of Hydraulics, Hydrology and Glaciology, ETH Zürich, Zürich, Switzerland f Atmosphere and Ocean Research Institute, The University of Tokyo, Kashiwa, Japan g Dipartimento di Scienze della Terra, Università di Firenze, Florence, Italy a r t i c l e i n f o a b s t r a c t Article history: Measuring glacier calving magnitude, frequency and location in high temporal resolution is necessary Received 13 November 2018 to understand mass loss mechanisms of ocean-terminating glaciers. We utilized calving-generated Received in revised form 14 February 2019 tsunami signals recorded with a pressure sensor for estimating the calving flux of Bowdoin Glacier Accepted 14 March 2019 in northwestern Greenland. We find a relationship between calving ice volume and wave amplitude. Available online 1 April 2019 This relationship was used to compute calving flux variation. The calving flux showed large spatial and Editor: J.P. Avouac 5 3 −1 temporal fluctuations in July 2015 and in July 2016, with a mean flux of 2.3 ± 0.15 × 10 m d . -
Protecting the Crown: a Century of Resource Management in Glacier National Park
Protecting the Crown A Century of Resource Management in Glacier National Park Rocky Mountains Cooperative Ecosystem Studies Unit (RM-CESU) RM-CESU Cooperative Agreement H2380040001 (WASO) RM-CESU Task Agreement J1434080053 Theodore Catton, Principal Investigator University of Montana Department of History Missoula, Montana 59812 Diane Krahe, Researcher University of Montana Department of History Missoula, Montana 59812 Deirdre K. Shaw NPS Key Official and Curator Glacier National Park West Glacier, Montana 59936 June 2011 Table of Contents List of Maps and Photographs v Introduction: Protecting the Crown 1 Chapter 1: A Homeland and a Frontier 5 Chapter 2: A Reservoir of Nature 23 Chapter 3: A Complete Sanctuary 57 Chapter 4: A Vignette of Primitive America 103 Chapter 5: A Sustainable Ecosystem 179 Conclusion: Preserving Different Natures 245 Bibliography 249 Index 261 List of Maps and Photographs MAPS Glacier National Park 22 Threats to Glacier National Park 168 PHOTOGRAPHS Cover - hikers going to Grinnell Glacier, 1930s, HPC 001581 Introduction – Three buses on Going-to-the-Sun Road, 1937, GNPA 11829 1 1.1 Two Cultural Legacies – McDonald family, GNPA 64 5 1.2 Indian Use and Occupancy – unidentified couple by lake, GNPA 24 7 1.3 Scientific Exploration – George B. Grinnell, Web 12 1.4 New Forms of Resource Use – group with stringer of fish, GNPA 551 14 2.1 A Foundation in Law – ranger at check station, GNPA 2874 23 2.2 An Emphasis on Law Enforcement – two park employees on hotel porch, 1915 HPC 001037 25 2.3 Stocking the Park – men with dead mountain lions, GNPA 9199 31 2.4 Balancing Preservation and Use – road-building contractors, 1924, GNPA 304 40 2.5 Forest Protection – Half Moon Fire, 1929, GNPA 11818 45 2.6 Properties on Lake McDonald – cabin in Apgar, Web 54 3.1 A Background of Construction – gas shovel, GTSR, 1937, GNPA 11647 57 3.2 Wildlife Studies in the 1930s – George M. -
PRESS RELEASE Icebergs A-70 and A-71 Calve from Larsen-D Ice Shelf in the Weddell
U.S. National Ice Center NOAA Satellite Operations Facility 4231 Suitland Road Suitland, MD 20746 PRESS RELEASE FOR IMMEDIATE RELEASE Contact: LT Falon Essary, NOAA [email protected] 3 01-817-3934 Icebergs A-70 and A-71 Calve from Larsen-D Ice Shelf in the Weddell Sea 08JAN2021, Suitland, MD — The Larsen-D Ice Shelf calved several icebergs in a calving event, two of which are large enough to be named. The breakup occurred in early November 2020, but until now it had been impossible to confirm whether these were icebergs large enough to be named or extremely old sea ice that had fasted to the ice shelf. Recent imagery showing surface topography typical of icebergs has allowed us to confirm these are indeed icebergs. The new iceberg A-70 is located at 72° 21' South, 59° 39' West and measures 8 nautical miles on its longest axis and 5 nautical miles on its widest axis. The new iceberg A-71 is located at 72° 31' South, 59° 31' West and measures 8 nautical miles on its longest axis and 3 nautical miles on its widest axis. A-70 and A-71 were first spotted by USNIC Ice Analyst Michael Lowe and confirmed by USNIC Ice Analyst Chris Readinger using the Sentinel-1A image shown below. Iceberg names are derived from the Antarctic quadrant in which they were originally sighted. The quadrants are divided counter-clockwise in the following manner: A = 0-90W (Bellingshausen/Weddell Sea) C = 180-90E (Western Ross Sea/Wilkesland) B = 90W-180 (Amundsen/Eastern Ross Sea) D = 90E-0 (Amery/Eastern Weddell Sea) When first sighted, an iceberg’s point of origin is documented by USNIC. -
SAR Image Observations of the A-68 Iceberg Drift Ludwin Lopez-Lopez1, Flavio Parmiggiani2, Miguel Moctezuma-Flores 1, and Lorenzo Guerrieri3 1UNAM, Fac
https://doi.org/10.5194/tc-2020-180 Preprint. Discussion started: 21 July 2020 c Author(s) 2020. CC BY 4.0 License. SAR image observations of the A-68 iceberg drift Ludwin Lopez-Lopez1, Flavio Parmiggiani2, Miguel Moctezuma-Flores 1, and Lorenzo Guerrieri3 1UNAM, Fac. Ingenieria, Cd. Universitaria, CDMX, 01430, Mexico 2CNR Institute of Polar Sciences, via Gobetti 101, Bologna, 40129, Italy 3INGV, via di Vigna Murata 605, Rome, 00143, Italy Correspondence: M. Moctezuma-Flores (mmoctezuma@fi-b.unam.mx) Abstract. A methodology for examining a temporal sequence of Synthetic Aperture Radar (SAR) images as applied to the detection of the A-68 iceberg and its drifting trajectory, is presented. Using an improved image processing scheme, the analysis covers a period of eighteen months and makes use of a set of Sentinel-1 images. A-68 iceberg calved from the Larsen C ice shelf in July 2017 and is one of the largest icebergs observed by remote sensing on record. After the calving, there was only a modest 5 decrease in the area (about 1%) in the first six months. It has been drifting along the east coast of the Antarctic Peninsula and it is expected to continue its path for more than a decade. It is important to track the huge A-68 iceberg to retrieve information on the physics of iceberg dynamics and for maritime security reasons. Two relevant problems are addressed by the image processing scheme presented here: (a) How to achieve quasi-automatic analysis using a fuzzy logic approach to image contrast enhancement, and (b) Adoption of ferromagnetic concepts to define a stochastic segmentation. -
Iceberg Calving Dynamics of Jakobshavn Isbrę, Greenland
ICEBERG CALVING DYNAMICS OF JAKOBSHAVN ISBRÆ, GREENLAND By Jason Michael Amundson RECOMMENDED: Advisory Committee Chair Chair, Department of Geology and Geophysics APPROVED: Dean, College of Natural Science and Mathematics Dean of the Graduate School Date ICEBERG CALVING DYNAMICS OF JAKOBSHAVN ISBRÆ, GREENLAND A THESIS Presented to the Faculty of the University of Alaska Fairbanks in Partial Fulfillment of the Requirements for the Degree of DOCTOR OF PHILOSOPHY By Jason Michael Amundson, B.S., M.S. Fairbanks, Alaska May 2010 iii Abstract Jakobshavn Isbræ, a fast-flowing outlet glacier in West Greenland, began a rapid retreat in the late 1990’s. The glacier has since retreated over 15 km, thinned by tens of meters, and doubled its discharge into the ocean. The glacier’s retreat and associated dynamic adjustment are driven by poorly-understood processes occurring at the glacier-ocean in- terface. These processes were investigated by synthesizing a suite of field data collected in 2007–2008, including timelapse imagery, seismic and audio recordings, iceberg and glacier motion surveys, and ocean wave measurements, with simple theoretical considerations. Observations indicate that the glacier’s mass loss from calving occurs primarily in sum- mer and is dominated by the semi-weekly calving of full-glacier-thickness icebergs, which can only occur when the terminus is at or near flotation. The calving icebergs produce long-lasting and far-reaching ocean waves and seismic signals, including “glacial earth- quakes”. Due to changes in the glacier stress field associated with calving, the lower glacier instantaneously accelerates by ∼3% but does not episodically slip, thus contradicting the originally proposed glacial earthquake mechanism. -
Iceberg Detection and Drift Simulation
Iceberg Detection and Drift Simulation W. Dierking1 Christine Wesche1, Armando Marino2 1Alfred Wegener Institute Helmholtz Center for Polar- and Marine Research, Bremerhaven, Germany 2The Open University, Engineering and Innovation Milton Keynes, United Kingdom Problems? - SAR images: • detection of small icebergs (Titanic: 15-30 m freeboard, 60-120 m length) • detection of icebergs in deformed sea ice - Iceberg drift forecasting Motivation for drift forecasting • marine safety • limit search area for new iceberg position in satellite images • reduce ambiguities in identifying particular bergs Detection: Thresholding WESCHE, C. and W. DIERKING, "Iceberg signatures and detection in SAR images in two test regions of the Weddell Sea, Antarctica". Journal of Glaciology. 2012, vol 58 (208), p. 325-339 • single-polarized images ERS-2 & Envisat ASAR icebergs & sea ice 25 m pixel • icebergs in open water and in sea ice • success of detection icebergs & sea ice is determined by 150 m pixel pre-processing • dependence of thresholds on wind/ice „dark“ icebergs conditions & open water 30 m pixel • problems in deformed sea ice Detection: Quad-Pol. Data Dierking, W., Wesche, C. (2014),”C-Band radar polarimetry – useful for detection of icebergs in sea ice?”, IEEE Transactions on Geoscience and Remote Sensing, Vol. 52, No. 1, 25-37 Use of polarimetric parameters improves discrimination between icebergs and sea ice only in some cases! Detection: Dual-pol incoherent Data Marino, A., Rulli, R., Wesche, C., Hajnsek, I. (2015) “A New Algorithm For Iceberg Detection With Dual-polarimetric SAR Data” Proc. IGARSS 2015, Milan, Italy. • icebergs present an enhanced volume scattering compared to sea ice and ocean surface (dual-pol. -
BASICS to REINFORCE Snowflat Ake.HOME My Snowfl Ake Will Look Different from All the Others Because Each One Is Unique
Family Newsletter THIS MONTH’S THEME Winter Wonderland Value Your Child’s In this icy adventure, your children will pretend to sled with penguins, Emerging Ideas run with snow leopards and build an When your child observes you valuing and integrating his ideas, his self-esteem will igloo. They will help rescue a baby increase. You can help boost your child’s confidence and self-esteem with these tips: polar bear from an iceberg and imagine skiing down a mountain. • Give your child choices where either choice is acceptable. For example, “Would you Experiment with melting ice and like to wear the blue shirt or the pink shirt?” In both choices the child is getting dressed. explore the Arctic in this sparkling, • Ask your child for his opinion when making decisions. snowy theme. Whether you are rearranging furniture or cooking Today I made a snowfl ake. I arranged craft sticks to design my own falling dinner, if you ask your child what he thinks, it shows BASICS TO REINFORCE snowflAT ake.HOME My snowfl ake will look different from all the others because each one is unique. I practiced thatmy you care enough to consider his opinions. spatial awareness skills when I moved the craft sticks to LETTERS Ii, Pp and Tt create the snowfl ake. • Follow the interests of your child when ASK ME Did you count NUMBERS how many points yourpossible. Incorporate his interests in activities 7 andDAILY 8 snowfl ake has? Where will you keep your snowfl ake? NOTES or discussions. • Encourage responsibility by giving your Week Ice & Snow child chores each day. -
Unit 3. Antarctic Oceanography Lesson 1
ANTARCTIC Unit 3. Antarctic Oceanography Lesson 1. – Overview and Research Stations Lesson Objectives: • Introduces the continent of Antarctica and the oceans that surround it • The student will learn about the geography, history and climate. • The second section of this chapter discusses research stations and the scientists who live on the frozen continent. Antarctica is a continent located form 25 million years ago. The at the southern-most point of ice in Antarctica locks up more the globe. Millions of years ago, than two-thirds of the planet's this landmass was attached to fresh water. If the Antarctic ice a giant landmass that consisted were to melt, the sea would rise of modern-day South America, almost 200 feet. It is the only India and Africa. Powerful underground forces ripped a large piece of land from this giant landmass, which then drifted to its current position at the bottom of the globe. It is surrounded on all sides by the Indian, Pacific and Atlantic Oceans. continent that man had left untouched for Antarctica's cold, thick hard millions of years. covering, called an Antarctica is ice considered the sheet, coldest and driest continent on began to earth. Temperatures decrease regions inland. Temperatures as one moves from the coastal during the long, dark winters ©PROJECT OCEANOGRAPHY ANTARCTIC OCEANOGRAPHY 87 ANTARCTIC range from –4° F to –22° F on Blizzards are produced not by the coast, -40° F to –90° F falling snow, but when high inland. During the summers, winds (100- 200mph) blow coastal temperatures average ground snow around, creating 32° F (occasionally climbing to blinding conditions and 50° F), while the inland summer snowdrifts that can cover local temperatures range from –4° F research stations in an hour. -
Sea Level Rise Experiment Name: ______Teacher Guide Date: ______
Sea Level Rise Experiment Name: ________________________Teacher Guide Date: ____________ Background: An iceberg is a large piece of ice that is floating freely in the water. Icebergs form when chunks of ice break off of glaciers, ice shelves, or a larger icebergs. A glacier is a large piece of ice on top of land. Glacier ice forms by the accumulation and compaction of snow. Glaciers typically occur on mountains or near the poles. Directions: 1. Gather your supplies (tub, clay (or large rock), ice cubes, water, ruler, tape, marker) to build your sea level rise model. 2. If you are using clay, mold it into an island and stick the clay to the bottom of your container. If you are using rocks, place them in the container. Make sure the island has a flat surface for your ice cubes (glaciers) to balance on. 3. Tape your sea level gauge (ruler) to the inside of the container so that you can measure the height of the water (sea level). 4. Add water to the container. Make sure the top of your island is above the water level! 5. Make some predictions based on your model: a. Imagine that you put an ice cube directly in the water. What does the ice represent? An iceberg. b. What will happen to the water level as the ice cube melts? The water level will stay the same as the iceberg melts because the floating iceberg is already balanced with the water level. NOTE 1: most of the iceberg is below the water level. NOTE 2: The water level WILL rise when the ice cube is first put in the water. -
Sea Ice and Iceberg Conditions, 1970-1979
NOT TO BE CITED WITHOUT PRIOR REFERENCE TO THE AUTHOR(S) Northwest Atlantic Fisheries Organization Serial No. N436 NAFO SCR Doc. 81/IX/130 THIRD ANNUAL MEETING - SEPTEMBER 1981 Sea Ice and Iceberg Conditions, 1970-1979 by Dr. Thomas C. Wolford Coast Guard Oceanographic Unit, Bldg. 159-E, Navy Yard Annex Washington, D.C. 20593, USA An iceberg is a mass of ice which originated- on land and has broken away from its parent formation on the coast and either floats in the ocean or is stranded on a shoaL An iceberg usually refers to an irregular mass of ice formed by the calving of a glacier along a coast where a glacier terminus reaches the ocean. An iceberg should be distinguished from a floeberg which is a mass of hummocked multiyear sea ice formed by the piling up (rafting) of many sea ice floes by lateral pressure. Sea ice on the other hand is formed by freezing seawater. These two distinct types of origin are the reason for the distinctly different characteristics and distribution of sea ice and icebergs. The areas of the eastern Arctic which produce icebergs that drift onto the Grand Banks are (Figure 1): The west coast of Greenland (Principally from Disko Bay to Cape York, Greenland) Ellesmere Island 3„ An occasional iceberg from East Greenland 4. Very rarely an ice island may enter Robeson Channel and break up creating many tabular icebergs (The last such occurence was 1963). Greenland produces approximately 98% of all icebergs drifting in Baffin Bay and the Labrador Sea. These icebergs are produced by approximately 20 glaciers.