Breaking of Antarctic Larsen C Ice Shelf: An inimical off-shoot of Climate Change

Debates of climate changed picked up traction with ignoble US president announcing the withdrawal of America from the Paris Climate Accord. Protesting the indifference of politicians towards the climate change environmentalists expressed their discontentment with massive protests at Hamburg where G-20 leaders assembled for the summit meet. Days after conclusion of the summit, European Space Agency, Sentinel-1 mission, announced that Larsen C ice-shelf, the fourth largest in the World (5800 sq km) comprising of 12% of total area of Antarctica broke off from the frozen continent.

Ice-shelves are humongous repositories which are formed when glaciers on land begin to spread out over the sea. They essentially prevent the drifting of glacial ice into sea and thereby regulate sea level rise. In general, glacial ice, chips off to form icebergs. Now snapping of 12 trillion cubic meters of ice, larger than Haryana, is believed to change the landscape of Antarctica. While the immediate effects of this event are not ominous, scientists are carefully monitoring rest of the ice-shelf closely. The ice shelf which looks like a crooked finger is pointing towards tip of the South America is an extension of huge West Antarctic Ice Sheet (WAIS). The ice-shelf when ripped off completely will exist as a 190-meter-thick iceberg nearly four times the height of Qutub Minar.

Indeed, fissures in the Larsen C ice-shelf first appeared in 2010. The tear which spread 10 meters per day gradually accelerated to 36 mt before finally snapped away on July 12th. Splintering of ice shelf has already begun and the smaller ice bergs are now heading towards Weddell Sea. Experts at Scripps Institute of Oceanography said that ice fragments might eventually move further north towards South Georgia and South Sandwich Islands.

Breaking of ice-shelf is a natural process. Antarctica ice is tightly compressed at the edges of its rocky base and under the weight of huge ice accumulations, ice shelves break off from time to time. Hence breaking of ice shelves can’t be attributed to global warming directly. But what caught the attention of the scientists is the shortened frequency of the calving (breaking of ice-shelves) process. Ice shelves which form 75% of coastal Antarctica are susceptible to changes in atmospheric temperature from above and ocean warming from below. Though the role of warm climates in triggering calving is not scientifically established as of now, experts believe don’t belie its role.

Gigantic Icy continent is firmly edged by ice-shelves which form the coastal region while glaciers impound inlands. Thwaites glaciers, a gigantic bulk of ice part of the West Antarctica Ice Sheet, located further inland has become cause of intense concern. Rapidly changing climates led to melting and sliding of the glaciers into sea pushing up sea levels. Unchecked greenhouse gas emissions accentuate melting of glaciers. It is estimated that melting of West Antarctica Ice Sheet can increase sea level by 3 meters. On the contrary, ice-shelf breaking may not increase the sea-level since this portion of ice was already in water. Volume of water produced after the ice shelf melting is equal to volume of ice that was displaced. But calving of ice-shelf and its gradual melting will greatly destabilize the land ice. Though scientists are hopeful that ice-shelf will regrow but chipping away of huge chunks of ice-shelves at regular intervals will inadvertently make Antarctica less stable. If the newly calved iceberg drifts into warm oceans, it can just long for few decades. Ice shelves act as sinks for glaciers and their calving will eventually hasten melting of glaciers leading to increase in sea-level. In 2015, a report in reputed journal Science warned that ice-shelves in Antarctica are thinning at an accelerated pace and that ice-shelves ceased to gain volume.

Larsen Shelf is named after the Norwegian explorer Carl Anton Larsen who in 1890, sailed along the 1000km western coastal stretch. The Larsen shelf comprises of distinct shelves- Larsen A, B, C and D. In 1995, Larsen A broke away and melted completely in seven years.  The 10,000 years old Larsen B separated from Antarctica in 2002 and became an iceberg. Reports showed that Larsen B calving speeded up glacier collapse by 300 to 800%. Larsen C is five times the size of Larsen B. NASA scientist Cavin Schmidt said that complete melt down of Larsen C might increase sea level by 0.1mm.

Intergovernmental Panel on Climate Changes Fifth Assessment Report (5AR), indicated that temperatures in Antarctic peninsula where Larsen-C is located, are rising four to six times that of global average. Though role of global warming wasn’t scientifically established as of now, reputed scientific journal, Nature, opined that increased human (anthropogenic) activity in Antarctica is posing new threat. Surge in number of tourists visiting Antarctica is drastically changing the delicate ecosystem of Antarctica. Especially visitors to coastal regions has increased from 1.5 million in 2004-05 to 2.6 million in 2013-14. Interestingly, Antarctica is in news recently for being the venue for first ever wedding ceremony of expedition leaders of British Antarctica Survey (BAS).

As per IPCC reports twentieth century witnessed a linear increase of sea-level caused by warmer oceans and melting glaciers. In 21^st century rise of sea-level is exponential because of melting of fast flowing glaciers and subsequent breaking of ice-shelves of Greenland and Antarctica. Already islands in the Pacific Ocean, Indian Ocean and countries with huge coasts are facing the inimical effects of global warming. Besides the impending threats of inundation, rising sea-levels are critically endangering livelihoods of thousands of people living along the coasts. Fertile cultivable lands are rendered barren by salty depositions. Fresh water resources are becoming salty. 

Mounting evidences unequivocally indicate that unscrupulous human activity has irrevocably disturbed delicate balance of nature. The irreversible damage can be controlled through collective action and committed nurture. It is time international collaboration be ramped up to tame the disastrous cycle of events triggered by global warming. But sadly, overpowered by ritualistic nationalism, America, the biggest emitter of greenhouse gases is dragging its feet. Abdicating responsibilities towards environment will push us closer to a brink of self-inflicted catastrophic consequences. Calving of Antarctic ice-shelf is an inimical distress signal lest the World choses to brush it off at its own peril.

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ISRO creates a World record by launching 104 satellites

ISRO reached yet another milestone. From its splendid journey of transporting the rockets on the bullock carts to reaching the stars, the persistence, dedication, and commitment of scientists has transformed the organization into an epitome of excellence. ISRO today scripted history by sending 104 satellites into space in a single go. On January 4^th 2017, ISRO announced that India will launch 104 satellites in one go at the Indian Science Congress held at Tirupati. Since then there has been a palpable excitement among the scientific community. ISRO had steadily climbed the ladder of competitive global markets of small satellite launching with an incredible consistency and economy. It is now reckoned as an iconic leader in commercial satellite launches. ISRO last year launched 20 satellites in one go.  Russian rocket launcher Dpner, a transformed inter-continental ballistic missile by launching a maximum of 39 satellites into space in a single launch in June 2014 created a record. NASA in 2013 launched 29 satellites. With Tuesday’s launch ISRO aims to surpass the earlier records. ISRO with its upcoming launch aims to display India’s satellite launching prowess.

PSLV- C37, the heaviest of all the PSLV series of rocket launchers lifted off from the Satish Dhawan Space Centre (SDSC), SHAR, Sriharikota on Feb 15^th at 9:28 carrying 104 satellites. Polar Satellite Launch Vehicle (PSLV) which has already earned a distinct reputation for its reliability and accuracy was specially designed to carry all these satellites. PSLV the formidable work-horse of ISRO in its XL configuration was assigned with the task of delivering the payloads.

PSLV-C37 weighing 320 ton and 44.4 m tall is a four-staged rocket launcher. On its thirty-ninth flight, 103 co-passengers accompanied the primary satellite Cartosat-2 series. Cartosat-2 with a work life of 5 years, weighing 714kg is an earth observation satellite like other four satellites in its series. This was injected into 505 km polar Sun Synchronous Orbit and will soon resume its remote sensing services using its panchromatic and multispectral cameras. These images are used for cartographic applications and for monitoring road networks, water distribution and land use. It was designed to monitor activities across India’s hostile borders. The other two Indian satellites are the ISRO nano satellites- INS 1A and INS 1B. They are designed for scientific experimentation. INS 1A, with six-month mission life, weighing 8.4kg has two pay loads - Surface Bidirectional Reflectance Distribution Function Radiometer and Single Event Upset Monitor. INS 1B, with six-month life cycle, weighs 9.7 kg and carries two pays - Earth Exosphere Lyman Alpha Analyzer and Origami Camera.

Of the remaining 101 satellites- 96 are from US, others are from Kazakhstan, Israel, The Netherlands, Switzerland, and UAE.  The total weight of all satellites on board PSLV-C37 is 1378 kg.  Satellites from US are mostly DOVE Flock-3P (designed and operated by Planet Inc) fleet of remote sensing satellites designed to earth every day for commercial, environmental, and humanitarian purposes and LEMUR satellites of Spire Global Inc are meant for weather measurements and tracking vessels using Automatic Identification System (AIS). The average weight of DOVE and LEMUR satellites is around 4.7 kg. Satellites from other countries are basically for technology demonstration and weigh less than 4.5 kg.

Though ISRO has convincingly demonstrated its impeccable scientific mettle earlier by sending 20 satellites simultaneously, the latest feat is five times more challenging. Science enthusiasts are increasingly curious as how ISRO will carry out this exceedingly excruciating task of putting 100 odd satellites into different orbits with precision. Dr. K. Sivan, director of the Vikram Sarabhai Space Centre explained that “the satellites will be separated from the launch vehicle in different directions. The separation angle and time of separation will be such that one satellite will not collide with another”. He pondered that each satellite separated from launch vehicle will have a relative velocity of one meter per second. So, the distance between satellite and vehicle after 1000 seconds will be 1000 meters. “The satellite that gets launched first will move at relatively faster velocity than the next satellite that is launched. Due to different relative velocities, the distance between the satellites will increase continuously but the orbit will be the same”. Thus, a degree of difference in separation angle together with relative velocity would ensure that no two satellites would ever collide. Further care would be taken for the orbital disturbances to die before preparing the satellite for separation. Moreover, “satellites will be injected into orbit at different locations at different angles, at different times and different orientations”. In less than 600 seconds, all satellites travelling at velocity of 27,000km per hour will be released into space. This scientific spectacle would thus be internationally judged for its immaculate execution.

ISRO’s resilient journey marred by several debacles over the decades had steadily acclaimed scientific reputation due to the phenomenal success rate of the trusted work-horse PSLV. India’s rapid march towards space exploration with its projects Chandrayaan-1 and Mangalyaan has placed India among the elite group of technologically advanced countries. Satellite launching industry is growing at a tremendous pace. As of now there are few reliable players in the market. India till now has launched 122 satellites of which 79 are of foreign payloads. From 2011 till August 2016, the commercial wing of ISRO, Antrix Corporation made a profit of Rs 896 crores. ISRO at present is carrying out 5-6 launches and plans to increase launches to 18 to substantially increase its revenue. ISRO’s current launch slated for Feb 15^th, if successful will greatly boost its position in the global satellite launching market.

ISRO is all now gearing up for much bolder space missions. Accordingly, government has increased fund allocation to Department of Space by 26% making provisions for Mars Orbiter Mission-II and Mission to Venus. France has expressed willingness to collaborate with ISRO for the second Mars mission slated for 2021-22. NASA is willing to partner with ISRO in India’s maiden voyage to Venus, the planet named after Goddess of love and beauty.

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