The Brief

Ships plying the frigid waters near the Antarctic Peninsula, south of South America, will need to keep an eye on their radar for a floating island of ice: "The largest iceberg in the world, A-23a, is on the move into open ocean!" as the British Antarctic Survey recently announced.

"It's a trillion tons of ice. So it's hard to comprehend just how big a patch of ice this is," Ted Scambos, a senior research scientist at the University of Colorado Boulder, told NPR.

Iceberg A23a measures 40 by 32 nautical miles, according to the U.S. National Ice Center. For comparison, Hawaii's island of Oahu is 44 miles long and 30 miles across. And New York City's Manhattan Island is about 13.4 miles long and spans around 2.3 miles at its widest point.

When A23a was still part of an ice shelf, it held a Soviet research station — and it whisked that base off to sea when it floated away in the 1980s (more on that below). The iceberg then became grounded on the seafloor. But in recent years, it has been on the move again, after shaking loose.

Here's a quick recap of the iceberg, its history and its potential future:

It's the world's biggest iceberg

A23a hasn't always held the title. In 2021, for instance, it was supplanted by iceberg A-76, which broke from the Ronne Ice Shelf, also in the Weddell Sea. But that giant soon fractured into smaller icebergs, putting A23a back into the top spot.

"It's truly a gargantuan piece of ice," Scambos said, noting that the iceberg is likely 1,000 to 1,200 feet thick.

Its roots stretch to the austral winter of 1986, when the Filchner Ice Shelf's leading edge broke off to calve three huge icebergs: A22, A23 and A24. In late 1991, A23a became a separate iceberg.

A23a was grounded for decades

Recent satellite images have shown the migration of the mammoth iceberg known as A23a from its origins in the Weddell Sea to its current position on the edge of the open ocean.

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Worldview/NASA Earth Observing System/Screenshot by NPR

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If icebergs were humans, A23a would be a millennial. And like members of that generation who have sometimes been forced to stay home by harsh economic conditions, the iceberg has spent most of its independent existence grounded, stuck to a sandbank in shallow waters.

Little by little, the iceberg kept scouring a path over the seafloor and toward deeper water, nudged by currents, the wind and other factors. A breakthrough came in 2020, when the main bulk of A23a freed itself and started to pivot clockwise on its southeast corner. Before long, it was moving in earnest.

It took ice station Druzhnaya 1 out to sea

A map shows the locations of research stations in Antarctica, focusing on the coast of the Weddell Sea.

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U.S. Geological Survey

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Over the decades, the Filchner Ice Shelf has hosted several countries' research and mapping stations. For about 10 years, that included a Soviet station called Druzhnaya 1.

"When the A23 iceberg calved and floated off" in 1986, "Druzhnaya 1 was still on it," according to the U.S. Geological Survey.

In February 1987, a Soviet ship, the Kapitan Kondratyev, tracked the iceberg down and deployed a landing party aboard a helicopter "to salvage the most valuable equipment from the station," as researchers noted in a recent academic paper.

Life can get weird on an iceberg

If you were to set foot on A23a, Scambos said, you likely wouldn't realize it's an iceberg, floating loose at sea. Its scale would simply fill the horizon; any movement would be imperceptible. He should know. He has camped on icebergs before.

He recalls one odd thing: the disorientation.

"The ice that the base was built on would start to rotate, and that would make the sun do funny things in the sky," Scambos said. "It wouldn't be where it's supposed to be in the morning or in the evening or at night — even though it's 24 hours of daylight."

Over the years, he has heard from people who want to visit an iceberg. And Scambos says that while some of their goals were outlandish (as in, people hoping to declare unilateral sovereignty over an ice kingdom), a gigantic iceberg like A23a is pretty stable — with a big caveat.

"It's not impossible to land on it," Scambos said. "I mean, the upper surface is going to be smooth and snowy and relatively safe, at least for now."

But as the iceberg drifts north and finds warmer conditions, melting and flooding will begin.

"Eventually it will start to crack apart fairly rapidly towards the end," he said. "You wouldn't want to be on it at the end, because the whole thing would be breaking off in pieces and falling into the ocean."

Huge icebergs have drifted far distances

Most icebergs emerging from the Weddell Sea tend to drift slightly eastward toward South Georgia, some 1,000 miles east of the tip of South America.

If that happens to A23a, it could run aground again near South Georgia. But other icebergs, like its sibling A24, have moved more directly north, toward the Falkland Islands.

"Usually they're in the process of breaking up at that point," Scambos said, "although this one is likely to survive longer than most because it came from a colder part of Antarctica" and is thick, along with having a heavy buildup of snowfall.

If A23a doesn't get hung up in shallow and warmer waters, he added, "it could wind up drifting south of Africa into the Indian Ocean. They've even drifted all the way into the Pacific and wound up coming up on Chile, almost circumnavigating the globe. Some of the largest icebergs have done that in the past."

You can learn a lot from an iceberg

Massive icebergs like A23a scrape and scour the seafloor in shallow waters.

"There's a lot of life that lives in the bottom of the ocean that is just completely crushed, wrecked, when one of these things passes over," Scambos said. "That's it for the ecosystem that lives in that part of the ocean."

But the icebergs also give scientists an idea of the changes wrought when massive plates of ice, formed in the coldest parts of the world, suddenly find themselves in warmer conditions.

"The main scientific source of interest for the iceberg is sampling ocean surface waters behind, near, and just ahead of it," Em Newton of the British Antarctic Survey said of A23a, in a message to NPR. Researchers, she added, want "to understand the effects of temperature, changes to salinity, released nutrients, etc., along its path."

This part of the Southern Ocean is normally very poor in nutrients. An iceberg like A23a, Scambos says, can help change that by shedding nutrients it accumulated from Antarctica and stirring up deep water, possibly sparking a plankton bloom in its wake.

What about climate change?

News of the iceberg's peregrination comes after record warm temperatures and low levels of sea ice have been recorded around Antarctica in recent years.

"In February 2023, sea ice around Antarctica reached the lowest extent ever observed since the start of the satellite record in 1979," the NASA Earth Observatory said.

And in September, researchers at the National Snow and Ice Data Center reported the lowest winter maximum extent of Antarctic sea ice. It was found to be nearly 400,000 square miles below the previous low, set in 1986.

"But despite several recent years of low extents, the long-term trend for sea ice in southern polar waters is essentially flat," the NASA Earth Observatory said, adding, "it is the declines in sea ice at the other pole — in the Arctic — that are pushing the global sea ice trend downward."

Scambos agrees, noting that A23a came from a part of Antarctica that is fairly stable.

"These big icebergs are spectacular, but they're just the way Antarctica works. This is how an ice sheet works. It gathers snow, and the snow thickens and flows off into the ocean, and then pieces break off. And in Antarctica, those pieces are really, really large," he said.

"But the more important thing for people to be aware of is that Antarctica in other places is losing ice very rapidly," Scambos said, describing a dynamic that contributes to rising sea levels.

"And that actually is a much more serious problem."

NASA astronauts Reid Wiseman, Victor Glover and Christina Koch and Canadian Space Agency astronaut Jeremy Hansen were ensconced in the Orion space capsule when they dropped into the Pacific Ocean off the coast of San Diego at 8:07 p.m. Friday. The USS John P. Murtha is stationed near the splashdown zone to help recover the crew.

The USS John P. Murtha is stationed near the splashdown zone and will help recover the crew. A team will head out to the floating capsule and install an inflatable raft just below Orion's side hatch. The crew will be examined by a flight surgeon, then helped out of the capsule. From the transport ship, they will hitch a ride back to Johnson Space Center in Houston.

Risk of reentry

There's always risk when returning from space. Glover said that he has been thinking about this portion of the mission since he was selected for it back in 2023, and he's been looking forward to it ever since.

"We have to get back," he said from the Orion capsule Wednesday. "There's so much data that you've seen already, but all the good stuff is coming back with us. There's so many more pictures, so many more stories, and, gosh, I haven't even begun to process what we've been through."

To get back, the capsule must hit the atmosphere at a precise angle.

"Let's not beat around the bush," said Jeff Radigan, Artemis II's lead flight director. "We have to hit that angle correctly. Otherwise, we're not going to have a successful reentry."

All eyes will be on the heat shield — this is the piece of hardware beneath the capsule that protects the crew from the extreme temperatures during reentry. NASA tested it out on Artemis I, the previous, uncrewed mission, and found that the heat shield wasn't performing as designed.

NASA mission planners and the Artemis II team worked on a way to mitigate that risk. Instead of "skipping" through the atmosphere like Artemis I, this mission would hit the atmosphere steeper and faster, limiting the time the spacecraft spends in those fiery, energetic moments of reentry.

"It's 13 minutes of things that have to go right," said Radigan. "I have a whole checklist in my head that we're going through of all the things that have to happen."

Mission success

The Artemis II mission is a key flight test for Orion, and thus far, mission managers have been pleased with the results. The spacecraft has taken humans farther from Earth than they've ever been, breaking a record set by Apollo 13 astronauts in 1970.

The crew tested the manual control of the spacecraft, which will be needed for future missions that will dock with a lunar landing system. The mission tested the spacecraft's life support systems and ability to keep four astronauts comfortable within the confined space.

Artemis II returned humans to the moon for the first time since the Apollo program over 50 years ago. And while some astronauts back then did see the far side of the moon, the Artemis II crew was able to observe it from a vantage point never before seen by humans. Their images and geological notes will help better determine what the moon is made of and where it came from.

While some of the astronauts' observations may help scientists understand the distant past, others will help mission managers better plan for the future. Case in point: The crew tested out the very first toilet to go to the moon, and it quickly ran into issues during flight. Multiple times during the trip, the crew had to use manual urinals instead. The issue, NASA said, was not with the toilet itself, but the system that dumps the urine overboard when it gets full.

The Orion capsule will return to NASA's Kennedy Space Center in Florida after the mission, where engineers will examine the spacecraft after its flight, including a closer look at the spacecraft's plumbing. The team will be picking apart the spacecraft to see how it performed — and make any necessary changes ahead of the next mission, Artemis III, set to launch next year.

An L.A. city official sounded the alarm Friday that homeless service providers may go bankrupt or have to lay off staff over major reimbursement delays that still haven’t been fixed by the region’s homeless services agency — despite promises two years ago to fix it.

The L.A. Homeless Services Authority (LAHSA) is late in reimbursing more than $50 million to shelter, housing and other service providers — much of which is more than 90 days overdue — according to a report it issued last month. One service provider said LAHSA is more than 90 days late in reimbursing more than $12 million in invoices to their organization.

”Everybody involved with contracting is frustrated, is angry, is exhausted," said John Wickham, the lead city staff member who presented about the issue to the city council’s Housing and Homelessness Committee on Friday. Wickham said the frustrations are shared by all of the city departments that deal with LAHSA, as well as LAHSA staff and service providers.

Wickham said he’s heard that some service providers may be considering layoffs or even considering filing for bankruptcy because of the delayed payments.

“ When payment delays occur, [service providers] are forced to make difficult decisions that everyone is experiencing right now,” said David Carpio, the chief operating officer for Veteran Social Services, Inc.

Those decisions, he said, include reducing available beds, limiting intake of new people for services, increasing wait times, ending projects — which he said leads to increased homelessness and burden on the city for emergency services calls.

Sharon Sandow, a spokesperson for the city housing department, said the department has paid LAHSA upfront — known as “advances” — so it has cash on hand to pay service providers. Sandow said the city has, at times, borrowed money from the General Fund to make advance payments to LAHSA.

Wickham said advanced payments from the city to LAHSA were being passed “ back and forth and around and around in circles.”

“ I actually haven't been able to get to the bottom of that myself,” Wickham said when asked why that’s happening. “Nobody [can] understand that.”

Wickham said he and colleagues have held over 100 meetings with officials to try to understand how the city contracts for homeless services, but some aspects were still unclear.

Officials promised to get payments back on track two years ago by streamlining their processes. Councilmember Nithya Raman, who has chaired the council’s homelessness committee for the past few years, said on Friday the city is “stuck” and has not fixed the issue.

“We don't have the ability at the city to manage this process any better than we did last year or the year before. We have just not moved forward at all,” she added. “It is extraordinarily frustrating, and those same issues persist at LAHSA that we've been discussing. So we're literally in the same place that we've been for two years.”

What LAHSA leaders say

The agency’s CEO, Gita O’Neill, told the committee the delays are “unacceptable” and that LAHSA is working with a consultant to improve its processes. LAHSA’s chief financial officer, Janine Trejo, said LAHSA “is accepting responsibility,” while she also pointed at the city for what she described as delays in the city finalizing its agreements to fund LAHSA and payments to LAHSA.

Mayor Karen Bass oversees the city agencies that pay LAHSA and is the only elected official on LAHSA’s governing commission, which she has served on for more than two years. She did not respond to a request for comment through a spokesperson on Friday’s discussion of the payment delays. Raman is running against Bass in the June primary election for mayor.

What’s next

Following up on City Council requests from years ago, the council committee plans to decide next Wednesday whether to recommend pulling all of the city’s funding out of LAHSA and having a different agency manage it. It will then go to the full City Council for a decision.

The Los Angeles County Board of Supervisors on Tuesday is expected to consider, a motion aimed at assessing the impact of the growing number of data centers in the region.

The centers have drawn criticism for their potential health and environmental effects on surrounding communities, and for the amount of energy they use.

Around the country, the growth in the number of data centers — which house servers, storage systems and other technology — has been driven in part by the proliferation of artificial intelligence, which has drastically increased the need for critical internet technology infrastructure.

There are already more than 70 established data centers in the county, with that number likely to grow as developers approach cities and the county to create additional facilities, according to the motion authored by Supervisor Hilda Solis.

“Establishing local regulatory oversight of data center placement and operation is needed to ensure community and environmental health and safety is protected,” the motion states. “As newer centers expand in scale and complexity, their energy use and environmental footprint is also increasing, with little community engagement on the potential impacts on residents’ health and wellbeing.”

A representative of the data storage industry raised concerns about the motion, which calls for a moratorium on data center development in unincorporated L.A. County that would be initiated “as applicable.”

“What concerns me most with the motion is the inclusion of a moratorium,” said Khara Boender, director of state policy for the Data Center Coalition. “That sends a strong signal as to whether they are welcome in those areas.”

Data centers ‘underregulated’

Solis’ motion calls on various departments including public health, public works and fire to provide findings regarding the health, environmental and safety impacts of data centers on neighboring communities, the impact on electrical and water resources and a review of how other jurisdictions around the county are regulating data centers within urban areas.

It also calls for a community education and outreach campaign to inform residents on potential impacts of advancing technologies.

The Natural Resources Defense Council, an environmental group, has said the data center industry is under-regulated and accelerating at a speed, scale and concentration that is impacting energy systems, water supplies, air quality, community health, land use and public finances.

A recent report by the group said state and local policymakers are at the forefront of this expansion, “uniquely positioned to guide it in ways that reflect local priorities and community needs, especially in the absence of federal guidelines.”

A fact sheet from the council said unrestricted buildout of data centers could come with big consequences including:

• Higher household water and energy bills
• Water scarcity 
• Increased water, air and noise pollution

The motion by Solis quotes a 2026 report by Community & Environmental Defense Services that showed pollutants emitted from data centers may adversely impact the health of individuals living as far as 0.6 miles from the site.

Boender, of the Data Center Coalition, said concerns about data centers have been overstated. In addition, she said data centers have “a lot of positive economic impacts associated with them.” She cited a Pricewaterhouse report that found one job in a data center creates six jobs in the broader economy.

Support for state legislation

In addition to asking county staff to assess the impact of data centers, the Solis motion calls on the county to support state legislation that directs the Public Utilities Commission to create a special rate structure for large-scale energy users and requires these users to pay for upfront transmission or distribution upgrades.

The county Board of Supervisors is expected to consider the motion during its regular meeting Tuesday. For more information, click here.

Democratic Rep. Eric Swalwell, one of the leading candidates for California governor, came under increasing pressure Friday to drop out of the race following a report by the San Francisco Chronicle that he sexually assaulted a former female staffer. Swalwell denied the allegations.

Several other Democratic candidates called for him to immediately drop out, including Superintendent of Public Instruction Tony Thurmond, San Jose Mayor Matt Mahan and former Controller Betty Yee, who called the allegations “sickening.”

Swalwell had racked up endorsements across the Democratic establishment, and at least one labor union and one politician who was backing him suspended their support swiftly Friday afternoon.

The Chronicle reported that a woman who worked in Swalwell’s Castro Valley office claimed to have had sexual encounters with him while she worked for him and alleged he sexually assaulted her when she was intoxicated. The report comes after weeks of rumors that Swalwell had inappropriate interactions with staff for years. On one instance in 2019, the woman said she became intoxicated after Swalwell asked her for drinks and woke up in his bed in a hotel room, feeling the effects of intercourse.

"These allegations are false and come on the eve of an election against the frontrunner for governor. For nearly 20 years, I have served the public — as a prosecutor and a congressman and have always protected women. I will defend myself with the facts and where necessary bring legal action,” Swalwell said in a statement Friday.

In recent weeks, two social media influencers began posting online what many people had considered rumors about Swalwell’s behavior with women. The influencers said they had spoken with several young women with whom Swalwell had behaved inappropriately. CalMatters has not independently verified the claims.

Swalwell pushed back hard against the allegations this week, telling reporters at a town hall in Sacramento on Tuesday that they are “false,” that he had “never” had a sexual relationship with anyone who worked for him. He suggested the allegations were politically motivated.

“I don’t want there to be any question in the minds of Californians,” he said. “I’m offering myself also as somebody who is fearlessly going to stand up for Californians on the toughest issues and not flinch.”

An attorney for Swalwell sent cease-and-desist letters to some of the women, one of the influencers, Arielle Fodor, wrote online. The attorney, Elias Dabaie, did not respond to a request for comment on the Chronicle story but confirmed to other news outlets the letter’s authenticity.

On Thursday night, Swalwell canceled a planned town hall in Southern California. Swalwell began calling groups that have endorsed him Friday morning to tell them of an upcoming story in the Chronicle, and denying the story, according to a person familiar with the matter who spoke to CalMatters.

At least four of his senior campaign staffers, including a top consultant who helped him court labor support, abruptly resigned before the news report.

Swalwell’s top two Democratic competitors in governor’s race, Tom Steyer and Katie Porter, on Friday avoided calling for him to drop out, though both issued statements commending the woman in the Chronicle story for coming forward.

Some groups that have endorsed Swalwell declined to comment on the allegations when reached by CalMatters, saying their board members needed time to digest the news.

For others, the exodus was swift. U.S. Rep. Jimmy Gomez, a Los Angeles Democrat who chaired Swalwell’s campaign, resigned from the role Friday and called on Swalwell to drop out. He called the allegations “the ugliest and most serious accusations imaginable.”

“My involvement in any campaign begins and ends with trust,” he said in a statement. “The congressman should leave the race now so there can be full accountability without doubt, distraction, or delay.”

The powerhouse union California Teachers Association immediately suspended its support of Swalwell, calling the allegations against him “incredibly disturbing and unacceptable” in a statement by President David Goldberg. “Our elected board will be meeting as soon as possible to follow our union’s democratic process to determine next steps.”

Another heavyweight union that endorsed him, Service Employees International Union California, suspended at least one ad buy in support of Swalwell following the accusations.

The California Medical Association, another backer, was convening an emergency meeting of the board, and “takes these allegations extremely seriously,” said spokesperson Erin Mellon.

CalMatters' Yue Stella Yu contributed to this report.

This article was originally published on CalMatters and was republished under the Creative Commons Attribution-NonCommercial-NoDerivatives license.