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Satellite imagery shows Antarctic ice shelf crumbling faster than thought

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(Last Updated On: August 11, 2022)

Antarctica’s coastal glaciers are shedding icebergs more rapidly than nature can replenish the crumbling ice, doubling previous estimates of losses from the world’s largest ice sheet over the past 25 years, a satellite analysis showed on Wednesday.

The first-of-its-kind study, led by researchers at NASA’s Jet Propulsion Laboratory (JPL) near Los Angeles and published in the journal Nature, raises new concern about how fast climate change is weakening Antarctica’s floating ice shelves and accelerating the rise of global sea levels, Reuters reported.

The study’s key finding was that the net loss of Antarctic ice from coastal glacier chunks “calving” off into the ocean is nearly as great as the net amount of ice that scientists already knew was being lost due to thinning caused by the melting of ice shelves from below by warming seas.

Taken together, thinning and calving have reduced the mass of Antarctica’s ice shelves by 12 trillion tons since 1997, double the previous estimate, the analysis concluded.

The net loss of the continent’s ice sheet from calving alone in the past quarter-century spans nearly 37,000 sq km, an area almost the size of Switzerland, according to JPL scientist Chad Greene, the study’s lead author.

“Antarctica is crumbling at its edges,” Greene said in a NASA announcement of the findings. “And when ice shelves dwindle and weaken, the continent’s massive glaciers tend to speed up and increase the rate of global sea level rise.”

The consequences could be enormous. Antarctica holds 88% of the sea level potential of all the world’s ice, he said.

Ice shelves, permanent floating sheets of frozen freshwater attached to land, take thousands of years to form and act like buttresses holding back glaciers that would otherwise easily slide off into the ocean, causing seas to rise.

When ice shelves are stable, the long-term natural cycle of calving and re-growth keeps their size fairly constant.

In recent decades, though, warming oceans have weakened the shelves from underneath, a phenomenon previously documented by satellite altimeters measuring the changing height of the ice and showing losses averaging 149 million tons a year from 2002 to 2020, according to NASA.

The losses measured from calving outpaced natural ice shelf replenishment so greatly that researchers found it unlikely Antarctica can return to pre-2000 glacier levels by the end of this century.

The accelerated glacial calving, like ice thinning, was most pronounced in West Antarctica, an area hit harder by warming ocean currents. But even in East Antarctica, a region whose ice shelves were long considered less vulnerable, “we’re seeing more losses than gains,” Greene said.

One East Antarctic calving event that took the world by surprise was the collapse and disintegration of the massive Conger-Glenzer ice shelf in March, possibly a sign of greater weakening to come, Greene said.

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Apple loses top phonemaker spot to Samsung as iPhone shipments drop, IDC says

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(Last Updated On: April 16, 2024)

Apple’s (AAPL.O), opens new tab smartphone shipments dropped about 10% in the first quarter of 2024, hurt by intensifying competition by Android smartphone makers aiming for the top spot, data from research firm IDC showed on Sunday.

Global smartphone shipments increased 7.8% to 289.4 million units during January-March, with Samsung (005930.KS), opens new tab, at 20.8% market share, clinching the top phonemaker spot from Apple, Reuters reported.

The iPhone-maker’s steep sales decline comes after its strong performance in the December quarter when it overtook Samsung as the world’s No.1 phone maker. It’s back to the second spot, with 17.3% market share, as Chinese brands such as Huawei gain market share.

Xiaomi, one of China’s top smartphone makers, occupied the third position with a market share of 14.1% during the first quarter, read the report.

South Korea’s Samsung, which launched its latest flagship smartphone lineup – Galaxy S24 series – in the beginning of the year, shipped more than 60 million phones during the period.

Global sales of Galaxy S24 smartphones jumped 8%, compared to last year’s Galaxy S23 series during their first three weeks of availability, data provider Counterpoint previously said.

In the first quarter, Apple shipped 50.1 million iPhones, down from 55.4 million units it shipped same period last year, according to IDC.

Apple’s smartphone shipments in China shrank 2.1% in the final quarter of 2023 from a year earlier.

The drop underscores the challenges facing the U.S. firm in its third biggest market, as some Chinese companies and government agencies limit employees’ use of Apple devices, a measure that mirrors U.S. government restrictions on Chinese apps on security grounds.

The Cupertino, California-based company in June will hold its Worldwide Developers Conference (WWDC), where it will highlight updates to the software powering iPhones, iPads, and other Apple devices.

Investors are closely watching for updates on artificial intelligence development at Apple, which has so far spoken little about incorporating the AI technology into its devices. The company earlier this year lost the crown as the world’s most valuable company to Microsoft (MSFT.O), opens new tab, Reuters reported.

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China launch of relay satellite Queqiao-2 for lunar probe mission successful

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(Last Updated On: April 12, 2024)

China National Space Administration (CNSA) said on Friday its launch of a key signal relay satellite was a “complete success” and it would serve as the communication bridge for its future lunar probe missions for years to come, state media reported.

China launched the satellite Queqiao-2, which was named after a mythological bridge made of magpies, and two miniature satellites, Tiandu-1 and Tiandu-2, on March 20.

Queqiao-2 will be used as a communications bridge between the ground operations on earth and upcoming lunar probe missions on the far side of the moon until at least 2030.

The moon’s near side always faces earth. That means data transfers from the far side are impossible because there is no direct line of sight.

Queqiao-2 researcher and developer Xiong Liang described the satellite as “the main switch” of the whole fourth phase of lunar missions, according to state television CCTV.

“Only when the main switch is flipped on, all the communications can kick off,” Xiong said.

Queqiao-2 will orbit the moon and relay signals to and from the Chang’e-6 mission, which expected to be launched in May. The robotic Chang’e-6 probe will seek to retrieve samples from an ancient basin, acquiring lunar material from the moon’s hidden side for the first time.

Queqiao-2 will also be used as a relay platform for the Chang’e-7 lunar mission in 2026 and the Chang’e-8 mission in 2028.

The functions and performance of Queqiao-2 met mission requirements and it will be able to provide relay communication services for China’s lunar exploration projects and future lunar missions for China and other countries, said the CNSA, according to CCTV.

Queqiao-2 entered its targeted elliptical orbit on April 2 after a correction midway, near-moon braking and orbital manoeuvre around the moon, CNSA said.

The satellite has successfully communicated with Chang’e 4, which was the first spacecraft to perform a soft landing on the far side of the moon and is still carrying out its exploration mission. It also communicated with the Chang’e-6 probe while it is still on the ground earlier this month.

The successful launch of Queqiao-2 comes after the failed launch of another lunar spacecraft DRO-A/B satellites, which was intended to enter the moon’s distant retrograde orbit (DRO).

China has not released any information on whether or not the satellites can be retrieved.

 

(Reuters)

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Russia aborts planned test launch of new heavy-lift space rocket

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(Last Updated On: April 11, 2024)

Russian space officials on Tuesday aborted the test launch of a new heavy-lift rocket from its far-eastern launch pad.

The Angara-A5 rocket was scheduled to lift off from the Vostochny space launch facility at 0900 GMT Tuesday, but the launch was aborted two minutes before, AP reported.

Yuri Borisov, head of Roscosmos state space corporation, said the automatic safety system canceled the launch after registering a flaw in the oxidizer tank pressurization system.

He said the next launch attempt was set for Wednesday.

Tuesday’s launch was to be the fourth for the Angara-A5, a heavy-lift version of the new Angara family of rockets that has been developed to replace the Soviet-designed Proton rockets.

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