Monitoring of Ice Shelves With Specific emphasis on Antarctic Shelves

P. Jayaprasad Scientist

Microwave Technique Development Division, AMHTDG/EPSA Space Applications Centre, ISRO, Ahmedabad, India email: [email protected]

TREES Training on “Cryospheric Applications using Space Based Observations” 12-10-2017 09:30 -10:30

Antarctica, the southernmost continent, is an ice-covered land mass.

90% of world’s fresh water is in Antarctica.

It is broadly divided in to and .

Antarctic Peninsula is one of the test beds for monitoring climate variation.

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TREES Training on “Cryospheric Applications using Space Based Observations” 12-10-2017 09:30 -10:30 Antarctic Ice Features

The broader categories of ice features of Antarctica include

Ice Sheet (ice layer covering landmass over an extensive period)

Ice Shelf (Floating sheet of ice permanently attached to land mass)

Iceberg (the floating land ice)

Glaciers (slowly moving ice mass)

Ice Rise (grounded ice shelf)

Sea Ice (frozen ocean water)

TREES Training on “Cryospheric Applications using Space Based Observations” 12-10-2017 09:30 -10:30 Indian Antarctic Research Programme Indian Research Stations

India, with its two Indian Antarctic research stations Maitri and Bharati, have also been contributing in routine scientific expeditions and scientific research.

A Monitoring System is required pertaining to Bharati and Maitri, during the Indian Scientific Expedition to Antarctica during December – April .

This will help in easy ship navigation as it has to cut through the sea ice

TREES Training on “Cryospheric Applications using Space Based Observations” 12-10-2017 09:30 -10:30 Indian Research Stations: Bharati and Maitri

TREES Training on “Cryospheric Applications using Space Based Observations” 12-10-2017 09:30 -10:30 Maitri and Surroundings:RISAT-1 FRS-1 FCC (RH, RV, RV-RH)- 30 Dec 2014

Maitri RS and Priyadarshini Lake

Shivling

Blue Ice

TREES Training on “Cryospheric Applications using Space Based Observations” 12-10-2017 09:30 -10:30 RISAT-1 FRS-1 FCC(rh/rv/rh-rv)- 30 Dec 2014

Priyadarshini Lake

TREES Training on “Cryospheric Applications using Space Based Observations” 12-10-2017 09:30 -10:30 Bharati Peninsula and Surroundings

FRS-1 28 Dec 2014-Mosaic (Two Scenes)

Bharati Peninsula

Academic Federo

TREES Training on “Cryospheric Applications using Space Based Observations” 12-10-2017 09:30 -10:30 Bharati: 08 Feb 2015 LISS4

Bharati Research Stn

Communication and Remote Sensing Antennae

TREES Training on “Cryospheric Applications using Space Based Observations” 12-10-2017 09:30 -10:30 Ice Shelf

What is an Ice Shelf ?

A Thick, permanent, floating sheet of ice that is derived from terrestrial tributary glaciers.

Ice shelves are floating ice, connected to the mainland.

Ice shelves surround 75% of Antarctica’s coastline, and cover an area of over 1.561 million square kilometres

TREES Training on “Cryospheric Applications using Space Based Observations” 12-10-2017 09:30 -10:30 Ice shelf: Explained

TREES Training on “Cryospheric Applications using Space Based Observations” 12-10-2017 09:30 -10:30 Antarctic Ice Features: Specific Emphasise to Shelves

XII International Symposium on Antarctic Earth TREES Training on “CryosphericSciencesApplications using Space Based Observations ” 12-10-2017 09:30 -10:30 TREES Training on “Cryospheric Applications using Space Based Observations” 12-10-2017 09:30 -10:30 Ice Shelf

The ice shelf is in constant motion:

rising with the tides,

splitting off icebergs at its edges,

and growing again as inland glaciers feed it.

TREES Training on “Cryospheric Applications using Space Based Observations” 12-10-2017 09:30 -10:30 Ice Shelf and Sea Level Rise

Ice Shelf, no matter how large, is free floating now (that is not sitting on solid ground on Antarctica)

It has already raised sea level as much as it ever will.

If a chunk of ice now sitting on solid land should somehow slide into the ocean or melt it would raise sea level accordingly.

Take a glass and put 2-3 ice cubes in it then fill it with water until water level is to the top of the glass and let it sit.

After the ice melts the water level will be exactly the same as before. TREES Training on “Cryospheric Applications using Space Based Observations” 12-10-2017 09:30 -10:30 Ice Shelf: Mass Gain

Receive ice from

Glaciers flowing into them from the mainland

Accumulation from snow directly onto the ice shelf

Sea water freezing onto the bottom of the ice shelf.

TREES Training on “Cryospheric Applications using Space Based Observations” 12-10-2017 09:30 -10:30 Ice Shelf: Mass Loss

Ice loss from shelves are followed by progressive thinning by warm ocean waters below, from excessive melting during a warm summer above.

Ice Calving

TREES Training on “Cryospheric Applications using Space Based Observations” 12-10-2017 09:30 -10:30 Antarctic Ice Shelves

•Filchner-Ronne Ice Shelf •Brunt Ice Shelf •Riiser-Larsen Ice Shelf Crosson Ice Shelf •Quar Ice Shelf Shackleton Ice Shelf Cosgrove Ice Shelf •Ekstrom Ice Shelf Voyeykov Ice Shelf Abbot Ice Shelf •Jelbart Ice Shelf Cook Ice Shelf Venable Ice Shelf •Fimbul Ice Shelf Slava Ice Shelf Stange Ice Shelf •Lazarev Ice Shelf Gillett Ice Shelf Bach Ice Shelf •King Baudouin Ice Shelf Nansen Ice Sheet George VI Ice Shelf •Hannan Ice Shelf McMurdo Ice Shelf Wilkins Ice Shelf •Zubchatyy Ice Shelf Ross Ice Shelf Larsen Ice Shelf •Wyers Ice Shelf Swinburne Ice Shelf Ronne Ice Shelf •Edward VIII Ice Shelf Sulzberger Ice Shelf •Amery Ice Shelf Nickerson Ice Shelf •Publications Ice Shelf Getz Ice Shelf Wordie Ice Shelf •West Ice Shelf Dotson Ice Shelf Jones Ice Shelf Moscow University Ice Müller Ice Shelf Shelf Prince Gustav Ice Shelf Larsen Ice Shelf (A)

TREES Training on “Cryospheric Applications using Space Based Observations” 12Collapsed-10-2017 09:30 Ice -10:30 Shelves TREES Training on “Cryospheric Applications using Space Based Observations” 12-10-2017 09:30 -10:30 Fimbul Ice Shelf

TREES Training on “Cryospheric Applications using Space Based Observations” 12-10-2017 09:30 -10:30 WHY TO MONOTOR SHELF Ice shelves are important indicators of climate change

As they play a role in the stability of the Antarctic Ice Sheet and the ice sheet’s mass balance

For ocean stratification and bottom water formation; this helps drive the world’s thermohaline circulation.

Most mass loss from the Antarctic continent is from ice shelves,

Most of this is from just a few small ice shelves around the and West Antarctica.

Melting from beneath ice shelves is one of the key ways in which the Antarctic Ice Sheet loses mass

Icebergs cause hindrance to Navigation

TREES Training on “Cryospheric Applications using Space Based Observations” 12-10-2017 09:30 -10:30 Decadal Changes on Antarctic Ice Margins

TREES Training on “Cryospheric Applications using Space Based Observations” 12-10-2017 09:30 -10:30 Advancing and Retreating Shelves

TREES Training on “Cryospheric Applications using Space Based Observations” 12-10-2017 09:30 -10:30 Ice Sheet Contribution

Together, the ice sheets from Greenland and Antarctica hold more than 99% of the world’s freshwater ice.

These are enormous stores of frozen water, held on land.

If they fully melted, Greenland and Antarctic would respectively cause 7.2 m and 61.1 m of global sea level rise.

As the climate changes, becoming either warmer or colder, important changes happen to these ice sheets at the pole.

Increases in air temperature have two effects upon these large ice masses.

TREES Training on “Cryospheric Applications using Space Based Observations” 12-10-2017 09:30 -10:30 Ice Sheet Contribution

Warmer temperatures cause more evaporation from the oceans, and therefore more snow will fall on the ice sheet.

However, higher temperature also cause heating of the ice sheet surface, leading to increased melting, at a rate greater than the increase in snowfall.

As the edges of both the Greenland and Antarctic ice sheets are in the ocean, the temperature of the ocean also has a large effect on ice sheets.

Changes in ocean temperature can increase or decrease the amount of melting the ice sheet experiences, adding more or less water to the ocean.

TREES Training on “Cryospheric Applications using Space Based Observations” 12-10-2017 09:30 -10:30 Difference between Ice shelf and Sea Ice

Ice shelves are composed of ice derived from snowfall on land, but they also accrete marine ice from below

Sea ice, which form solely from freezing marine water.

TREES Training on “Cryospheric Applications using Space Based Observations” 12-10-2017 09:30 -10:30 Ice Calving

Ice shelves intermittently calve large icebergs, which is a normal part of their ablation.

Around Antarctica, ice shelves form where mean annual temperatures are less than -9°C, with sequential break up of ice shelves as temperatures increase.

The geometry of the coastline is often important for determining where ice shelves will develop.

TREES Training on “Cryospheric Applications using Space Based Observations” 12-10-2017 09:30 -10:30 Ice Shelves Collapse

Several of the ice shelves around Antarctica have recently collapsed dramatically, rather than retreating in a slow and steady manner.

Larsen A collapsed in 1995, and Larsen B Ice Shelf famously collapsed in 2002. It has shrunk from 12,000 km2 in 1963 to 2400 km2 in 2010.

During February 2002, 3250 km2 were further lost through iceberg calving and fragmentation.

Larsen C is recent calved even though collapse is not in near future

TREES Training on “Cryospheric Applications using Space Based Observations” 12-10-2017 09:30 -10:30 Reasons for Collapse There are Ice shelves collapse in response to long term environmental changes, which cause on-going thinning and shrinking.

When certain thresholds are passed, catastrophic ice shelf disintegration through iceberg calving is initiated.

Before collapse, ice shelves first undergo a period of long-term thinning and basal melting, which makes them vulnerable.

Meltwater ponding on the surface and tidal flexure and plate bending then all contribute to rapid calving events and ice shelf disintegration.

Long-term thinning from surface and basal melting preconditions the ice shelf to collapse.

Negative mass balances on tributary glaciers can lead to thinning of the glaciers and ice shelves. TREES Training on “Cryospheric Applications using Space Based Observations” 12-10-2017 09:30 -10:30 Ice Shelf: Effects of Ice shelf Collapse

It changes the boundary conditions for the glaciers that flow into the ice shelf.

As a result, ice-shelf tributary glaciers accelerate, thin and recede following ice-shelf collapse.

So, although ice shelves are already floating and therefore do not contribute to sea level rise when they collapse, ice-shelf removal has significant consequences for the grounded glaciers on the mainland.

TREES Training on “Cryospheric Applications using Space Based Observations” 12-10-2017 09:30 -10:30 Indicators of Collapse: Surface Melting and Ponding

Increased atmospheric temperatures lead to surface melting and ponding on the ice surface.

Catastrophic ice-shelf collapsed tend to occur after a relatively warm summer season, with increased surface melting.

This meltwater melts downwards into the ice shelf, causing fractures and leading to rapid ice-berg calving.

Increased surface meltwater also leads to snow saturation, filling crevasses with water and increasing hydrostatic pressures.

TREES Training on “Cryospheric Applications using Space Based Observations” 12-10-2017 09:30 -10:30 RISAT-1 FRS-1 FCC(rh/rv/rh-rv)- 30 Dec 2014

TREES Training on “Cryospheric Applications using Space Based Observations” 12-10-2017 09:30 -10:30 Ice shelf buttressing

Ice shelves play a very important role in “buttressing” their tributary glaciers.

Glaciers that feed into ice shelves are held back by the ice shelf in front of them.

Even small ice shelves play an important role in regulating flow from ice streams that feed into them

With glaciers thinning, accelerating and receding in response to ice shelf collapse, more ice is directly transported into the oceans, making a direct contribution to sea level rise.

Sea level rise due to ice shelf collapse is as yet limited, but large ice shelves surrounding some of the major Antarctic glaciers could be at risk, and their collapse would result in a significant sea level rise contribution

TREES Training on “Cryospheric Applications using Space Based Observations” 12-10-2017 09:30 -10:30 Indian Satellites for Antarctic Ice Monitoring RISAT-1 FRS-1, MRS, CRS Images: overview & Full Resolution MRS

CRS FRS-1

TREES Training on “Cryospheric Applications using Space Based Observations” 12-10-2017 09:30 -10:30 Indian Satellites for Antarctic Ice Monitoring RESOURCESAT-2, LISS-4, LISS-3 and AWiFS at Full Resolution

LISS-3

AWiFS LISS-4

TREES Training on “Cryospheric Applications using Space Based Observations” 12-10-2017 09:30 -10:30 Ascending and Descending Modes of MRS and CRS

Second Last Day of Ship Departure (24 March)

Thin Sea Ice

Helping Ship Navigation through providing sea ice status maps

TREES Training on “Cryospheric Applications using Space Based Observations” 12-10-2017 09:30 -10:30 Blizzard in the India Bay as viewed by ResuorceSat-2 on 20 Feb 2015 High Velocity Snow Wind

Advanced Wide Field Sensor (AWiFS) Linear Self Scanning Sensor-LISS3

TREES Training on “Cryospheric Applications using Space Based Observations” 12-10-2017 09:30 -10:30 India Bay viewed by RISAT-1 MRS

Sea Ice Snow covered Sea Ice

Fast Ice

Ice Shelf Fast Ice Ice Rise

Ice Shelf Ice Rise Melt Stream Melt Stream Crevasses Crevasses

20 Feb 2015 22 Feb 2015

TREES Training on “Cryospheric Applications using Space Based Observations” 12-10-2017 09:30 -10:30 Maitri Coast: India Bay

MRSTREES MOSAIC Training on “Cryospheric Applications using Space Based Observations” 12-10-2017 09:30 -10:30 Reduction in Fast Ice in India Bay Temporal MRS data

TREES Training on “Cryospheric Applications using Space Based Observations” 12-10-2017 09:30 -10:30 Brocken Fast Ice Floes on Optical LISS 4 & MRS-1 Image

TREES Training on “Cryospheric Applications using Space Based Observations” 12-10-2017 09:30 -10:30 Ship Location ON FRS image

TREES Training on “Cryospheric Applications using Space Based Observations” 12-10-2017 09:30 -10:30 Ship Anchored in India Bay

March 24, 2015

TREES Training on “Cryospheric Applications using Space Based Observations” 12-10-2017 09:30 -10:30 Lazerav Ice Shelf and Ice Berg UK235

TREES Training on “Cryospheric Applications using Space Based Observations” 12-10-2017 09:30 -10:30 TREES Training on “Cryospheric Applications using Space Based Observations” 12-10-2017 09:30 -10:30 Amery Ice Shelf

TREES Training on “Cryospheric Applications using Space Based Observations” 12-10-2017 09:30 -10:30 Larsen C calving and Deformation

A huge portion of the Larsen C ice shelf (~50,000 km2) in Antarctic Peninsula calved away to an iceberg of area ~6200 km2 between 10th July and 12th July, 2017.

The iceberg is named as A 68 by scientific community.

This event was closely monitored by Team AMHTDG/EPSA/SAC since February 2017, ever since news of the possible detachment of Larsen C from the landmass, started appearing on internet and the results of rift was reported by us, through SACNET, VYOM and VEDAS.

This has created interest among the scientists working in the field of cryosphere science. TREES Training on “Cryospheric Applications using Space Based Observations” 12-10-2017 09:30 -10:30 TREES Training on “Cryospheric Applications using Space Based Observations” 12-10-2017 09:30 -10:30 References

1. Cook, A.J. & Vaughan, D.G. Overview of areal changes of the ice shelves on the Antarctic Peninsula over the past 50 years. The Cryosphere 4, 77-98 (2010). 2. Glasser, N.F., Scambos, T.A., Bohlander, J.A., Truffer, M., Pettit, E.C. & Davies, B.J. From ice-shelf tributary to tidewater glacier: continued rapid glacier recession, acceleration and thinning of Röhss Glacier following the 1995 collapse of the Prince Gustav Ice Shelf on the Antarctic Peninsula. Journal of Glaciology 57, 397-406 (2011). 3. Shepherd, A., Wingham, D., Payne, T. & Skvarca, P. Larsen ice shelf has progressively thinned. Science 302, 856-859 (2003). 5. Fricker, H.A. & Padman, L. Thirty years of elevation change on Antarctic Peninsula ice shelves from multimission satellite radar altimetry. Journal of Geophysical Research: Oceans 117, C02026 (2012).

TREES Training on “Cryospheric Applications using Space Based Observations” 12-10-2017 09:30 -10:30 6. Domack, E., Duran, D., Leventer, A., Ishman, S., Doane, S., McCallum, S., Amblas, D., Ring, J., Gilbert, R. & Prentice, M. Stability of the Larsen B ice shelf on the Antarctic Peninsula during the Holocene epoch. Nature 436, 681-685 (2005). 7. De Angelis, H. & Skvarca, P. Glacier surge after ice shelf collapse. Science 299, 1560-1562 (2003). 8. Reynolds, J.M. The structure of Wordie Ice Shelf, Antarctic Peninsula. British Antarctic Survey Bulletin 80, 57-64 (1988). 9. Doake, C.S.M. & Vaughan, D.G. Rapid disintegration of the Wordie Ice Shelf in response to atmospheric warming. Nature 350, 328-330 (1991). 10. Rignot, E., Jacobs, S., Mouginot, J. & Scheuchl, B. Ice Shelf Melting Around Antarctica. Science (2013).

TREES Training on “Cryospheric Applications using Space Based Observations” 12-10-2017 09:30 -10:30 Photographs by 35th ISEA Team Maya and Rajendra TREES Training on “Cryospheric Applications using Space Based Observations” 12-10-2017 09:30 -10:30 Thanks

XII International Symposium on Antarctic Earth TREES Training on “CryosphericSciencesApplications using Space Based Observations ” 12-10-2017 09:30 -10:30