{"id":202322,"date":"2025-12-26T06:16:23","date_gmt":"2025-12-26T06:16:23","guid":{"rendered":"https:\/\/www.newsbeep.com\/nz\/202322\/"},"modified":"2025-12-26T06:16:23","modified_gmt":"2025-12-26T06:16:23","slug":"the-ice-that-holds-up-half-a-meter-of-sea-level-begins-to-crack-like-a-windshield","status":"publish","type":"post","link":"https:\/\/www.newsbeep.com\/nz\/202322\/","title":{"rendered":"The ice that holds up half a meter of sea level begins to crack like a windshield"},"content":{"rendered":"<p>Most people have watched a crack spread, on a phone screen, a windshield, or a sidewalk after a brutal winter. Now scale that up to Antarctica, where <a href=\"https:\/\/www.ecoticias.com\/en\/huge-iceberg-breakoff-antarctica\/12912\/\" rel=\"nofollow noopener\" target=\"_blank\">cracks can run for miles<\/a> and the stakes are global.<\/p>\n<p>Scientists tracking <a href=\"https:\/\/nsidc.org\/our-research\/featured-projects\/international-thwaites-glacier-collaboration\" target=\"_blank\" rel=\"noopener nofollow\">Thwaites Glacier in West Antarctica<\/a>, commonly nicknamed the <a href=\"https:\/\/news.umanitoba.ca\/cracking-the-code-of-thwaites-ice-shelfs-disintegration\/\" target=\"_blank\" rel=\"noopener nofollow\">Doomsday Glacier<\/a>, say a specific cracking process is helping a key part of it lose stability. In a new University of Manitoba-led analysis, researchers used two decades of satellite images and GPS measurements to track how fractures grew across the <a href=\"https:\/\/agupubs.onlinelibrary.wiley.com\/doi\/10.1029\/2025JF008352\" target=\"_blank\" rel=\"noopener nofollow\">Thwaites Eastern Ice Shelf<\/a>.<\/p>\n<p>The short version is that the ice shelf has been gradually detaching from a pinning point, basically an underwater \u201cspeed bump\u201d that helps hold it in place. As that grip weakens, the <a href=\"https:\/\/www.ecoticias.com\/en\/scientists-warn-the-glacier-at-the-end-of-the-world-is-not-only-melting-but-is-now-tearing-apart-from-within\/24680\/\" rel=\"nofollow noopener\" target=\"_blank\">ice<\/a> upstream can move faster toward the ocean. That is the kind of far-away change that eventually turns into very real headaches for <a href=\"https:\/\/www.ecoticias.com\/en\/atlantic-ocean-discovery-amoc-overflow\/14425\/\" rel=\"nofollow noopener\" target=\"_blank\">coastal communities<\/a>.<\/p>\n<p>What exactly is the Thwaites Eastern Ice Shelf, and why does it matter?<\/p>\n<p>Thwaites Glacier sits in West Antarctica and flows toward the Amundsen Sea, where parts of it extend as <a href=\"https:\/\/www.ecoticias.com\/en\/chicago-sized-iceberg-ancient-life\/12750\/\" rel=\"nofollow noopener\" target=\"_blank\">floating ice<\/a>. One of those floating extensions, the Thwaites Eastern Ice Shelf (often shortened to TEIS), is partially confined and anchored at its northern end by a pinning point.<\/p>\n<p>Why should anyone outside Antarctica care? Because if Thwaites were to collapse entirely, it contains enough ice to raise <a href=\"https:\/\/www.ecoticias.com\/en\/sea-level-rise-nasa-warning-2024\/12503\/\" rel=\"nofollow noopener\" target=\"_blank\">global sea levels<\/a> <a href=\"https:\/\/sealevel.nasa.gov\/news\/152\/huge-cavity-in-antarctic-glacier-signals-rapid-decay\" target=\"_blank\" rel=\"noopener nofollow\">by about 65 centimeters<\/a>, or roughly 25 inches. Floating shelves like TEIS also provide buttressing, meaning they act like a brace or brake that helps slow the land-based ice behind them. When that brace weakens, it can make it easier for more ice to flow into the ocean over time.<\/p>\n<p>How can a pinning point turn into a problem instead of a stabilizer?<\/p>\n<p>A pinning point is a <a href=\"https:\/\/www.ecoticias.com\/en\/hidden-network-meters-below-antarctica\/21671\/\" rel=\"nofollow noopener\" target=\"_blank\">grounded feature under the water<\/a>, often a ridge, that a floating ice shelf presses against. Think of it like a doorstop: it can keep the door from swinging too far, until the door starts splintering around it.<\/p>\n<p>The University of Manitoba team reports that shearing, meaning sideways grinding and stretching, around a prominent shear zone (a stressed strip of ice where movement concentrates and cracking becomes more likely) upstream of the pinning point has been central to TEIS\u2019s progressive disintegration. In their account, the pinning point gradually shifted from being a stabilizing force to becoming part of the destabilization story as fractures accumulated and the shelf\u2019s connection weakened.<\/p>\n<p>What did satellite and GPS data from 2002 to 2022 actually show?<\/p>\n<p>Researchers combined <a href=\"https:\/\/www.ecoticias.com\/en\/sea-levels-rising-nasa-new-satellite\/23711\/\" rel=\"nofollow noopener\" target=\"_blank\">satellite imagery<\/a> and ice-flow measurements, along with in-situ GPS records (on-the-ice sensors that track movement), to reconstruct how fractures evolved and how ice speed changed over time. They tracked three focus areas across TEIS: the shear zone near the pinning point, a mid-shelf region, and an area upstream of the pinning point. Their analysis also references the Thwaites Western Ice Tongue (TWIT), another <a href=\"https:\/\/www.ecoticias.com\/en\/mega-iceberg-a23a-south-georgia\/11782\/\" rel=\"nofollow noopener\" target=\"_blank\">floating section<\/a> of the glacier.<\/p>\n<p>Here\u2019s how the thesis associated with the work breaks down the four stages of change over the 2002 to 2022 record.<\/p>\n<p>Time periodStage described in the study materials2002\u20132006TWIT-driven acceleration phase2007\u20132012TEIS and TWIT shear-margin disintegration phase2012\u20132017TWIT disintegration phase2017\u20132022TEIS mid-shelf acceleration phase<\/p>\n<p>Across those stages, the researchers describe fractures developing in two main phases: first, long fractures aligned with ice flow, followed later by shorter fractures oriented across the flow. This created a positive feedback loop: fracture damage and faster ice flow amplified each other, accelerating the shelf\u2019s breakdown once key connections weakened.<\/p>\n<p>What does this mean for sea-level rise, and what can people do now?<\/p>\n<p>The study\u2019s immediate focus is mechanical: how cracking and shearing help an ice shelf detach from a pinning point and lose stability. But the broader implication is familiar: losing <a href=\"https:\/\/www.ecoticias.com\/en\/they-were-searching-for-shackletons-ship-and-found-a-gigantic-ghost-town-of-fish-hidden-under-the-ice\/24335\/\" rel=\"nofollow noopener\" target=\"_blank\">floating ice shelves<\/a> can reduce the <a href=\"https:\/\/www.jpl.nasa.gov\/news\/nasa-studies-find-previously-unknown-loss-of-antarctic-ice\/\" target=\"_blank\" rel=\"noopener nofollow\">buttressing<\/a> effect that slows inland ice, which can affect how quickly ice is delivered to the ocean over time. The researchers also point to this pattern as a warning sign that could matter for other Antarctic ice shelves showing similar weakening.<\/p>\n<p>If sea-level rise feels like background noise, you\u2019re not alone. Still, a little planning beats getting surprised later, especially since paperwork tends to show up right when you least want it.<\/p>\n<p>Check local flood-risk maps (including <a href=\"https:\/\/www.fema.gov\/flood-maps\" target=\"_blank\" rel=\"noopener nofollow\">FEMA flood maps<\/a>) and note whether your home, commute, or workplace is in a higher-risk zone.<\/p>\n<p>Review your insurance documents to see whether flooding is covered, because many policies treat flooding as its own category.<\/p>\n<p>Save digital copies of key records (ID, insurance, home inventory) somewhere you can access quickly.<\/p>\n<p>If you rent, ask your landlord what the building\u2019s flood plan is, and what you\u2019re responsible for versus what they cover.<\/p>\n<p>Follow updates from official science agencies and local emergency management offices so you\u2019re not relying on rumor-level doomscrolling.<\/p>\n<p>None of this changes what\u2019s happening on an ice shelf in <a href=\"https:\/\/www.ecoticias.com\/en\/antarctica-new-geothermal-energy-source\/10188\/\" rel=\"nofollow noopener\" target=\"_blank\">West Antarctica<\/a>. It does help you stay ahead of the practical consequences that scientists are word impacts of these large-scale changes.<\/p>\n","protected":false},"excerpt":{"rendered":"Most people have watched a crack spread, on a phone screen, a windshield, or a sidewalk after a&hellip;\n","protected":false},"author":2,"featured_media":202323,"comment_status":"","ping_status":"","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[22],"tags":[273,111,139,69,147],"class_list":{"0":"post-202322","1":"post","2":"type-post","3":"status-publish","4":"format-standard","5":"has-post-thumbnail","7":"category-environment","8":"tag-environment","9":"tag-new-zealand","10":"tag-newzealand","11":"tag-nz","12":"tag-science"},"_links":{"self":[{"href":"https:\/\/www.newsbeep.com\/nz\/wp-json\/wp\/v2\/posts\/202322","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.newsbeep.com\/nz\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.newsbeep.com\/nz\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.newsbeep.com\/nz\/wp-json\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/www.newsbeep.com\/nz\/wp-json\/wp\/v2\/comments?post=202322"}],"version-history":[{"count":0,"href":"https:\/\/www.newsbeep.com\/nz\/wp-json\/wp\/v2\/posts\/202322\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.newsbeep.com\/nz\/wp-json\/wp\/v2\/media\/202323"}],"wp:attachment":[{"href":"https:\/\/www.newsbeep.com\/nz\/wp-json\/wp\/v2\/media?parent=202322"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.newsbeep.com\/nz\/wp-json\/wp\/v2\/categories?post=202322"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.newsbeep.com\/nz\/wp-json\/wp\/v2\/tags?post=202322"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}