{"id":112098,"date":"2025-08-02T04:49:10","date_gmt":"2025-08-02T04:49:10","guid":{"rendered":"https:\/\/www.europesays.com\/us\/112098\/"},"modified":"2025-08-02T04:49:10","modified_gmt":"2025-08-02T04:49:10","slug":"antarctic-iceberg-downsizes","status":"publish","type":"post","link":"https:\/\/www.europesays.com\/us\/112098\/","title":{"rendered":"Antarctic Iceberg Downsizes"},"content":{"rendered":"

\"A<\/a><\/p>\n

Almost 40 years after breaking from Antarctica\u2019s Filchner Ice Shelf, a still massive iceberg is showing its age. The berg, named A-23A, is shedding large chunks of ice as it drifts in the southern South Atlantic Ocean, about 2,400 kilometers (1,500 miles) north of its birthplace.<\/p>\n

Starting around March 1, 2025<\/a>, the iceberg sat lodged<\/a> on the shallow continental shelf around South Georgia, the largest of nine remote islands that compose the South Georgia and South Sandwich Islands. Icebergs that make it this far north are increasingly at the mercy of warm water, waves, and seasonal weather\u2014factors that contribute to a berg\u2019s ultimate demise.<\/p>\n

After losing some pieces<\/a> from its edge, A-23A wiggled off the shelf by late May 2025 and resumed its drift toward the eastern side of South Georgia, following the same currents<\/a> previously ridden by the massive A-68A iceberg in late 2020. The austral winter journey continued to inflict damage on A-23A, which shed even more ice from its sides.<\/p>\n

Two of the new pieces were large enough to be named and tracked by the U.S. National Ice Center<\/a> (USNIC). Jan Lieser of Australia\u2019s Bureau of Meteorology first identified the bergs using NovaSAR-1<\/a> radar data, and they were later confirmed<\/a> by USNIC analyst Britney Fajardo in radar images acquired by the European Space Agency\u2019s Sentinel-1<\/a> mission on July 15, 2025. \u201cRadar satellites can take images of the Earth at polar night and through all weather conditions, including heavy clouds and even smoke,\u201d Lieser said.<\/p>\n

As sunlight returns to Antarctica after the polar night, Lieser also checks for icebergs in visible imagery. A break in the clouds and lengthening daylight hours on July 22, 2025, allowed the MODIS<\/a> (Moderate Resolution Imaging Spectroradiometer) on NASA\u2019s Aqua<\/a> satellite to capture this natural-color image of A-23A and the new bergs near South Georgia. Around this time, A-23A\u2019s surface spanned 2,510 square kilometers (969 square miles). The new pieces, A-23D and A-23E, measured 159 and 73 square kilometers (62 and 28 square miles), respectively.<\/p>\n

Despite these edge losses, A-23A is still the largest iceberg currently drifting freely in any of the world\u2019s oceans. (Only D-15A is larger, but that berg lies grounded in the cold Amery Sea off East Antarctica.) As lengthening daylight hours come to this part of the South Atlantic, scientists expect more calving from the remnant of A-23A as it moves even farther north.<\/p>\n

NASA Earth Observatory image by Michala Garrison, using MODIS data from NASA EOSDIS LANCE<\/a> and GIBS\/Worldview<\/a>. Story by Kathryn Hansen, with science review by Christopher Shuman, UMBC (retired).<\/p>\n","protected":false},"excerpt":{"rendered":"Almost 40 years after breaking from Antarctica\u2019s Filchner Ice Shelf, a still massive iceberg is showing its age.…\n","protected":false},"author":3,"featured_media":112099,"comment_status":"","ping_status":"","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[23],"tags":[746,159,67,132,68],"class_list":{"0":"post-112098","1":"post","2":"type-post","3":"status-publish","4":"format-standard","5":"has-post-thumbnail","7":"category-environment","8":"tag-environment","9":"tag-science","10":"tag-united-states","11":"tag-unitedstates","12":"tag-us"},"share_on_mastodon":{"url":"https:\/\/pubeurope.com\/@us\/114957370249086319","error":""},"_links":{"self":[{"href":"https:\/\/www.europesays.com\/us\/wp-json\/wp\/v2\/posts\/112098","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.europesays.com\/us\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.europesays.com\/us\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.europesays.com\/us\/wp-json\/wp\/v2\/users\/3"}],"replies":[{"embeddable":true,"href":"https:\/\/www.europesays.com\/us\/wp-json\/wp\/v2\/comments?post=112098"}],"version-history":[{"count":0,"href":"https:\/\/www.europesays.com\/us\/wp-json\/wp\/v2\/posts\/112098\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.europesays.com\/us\/wp-json\/wp\/v2\/media\/112099"}],"wp:attachment":[{"href":"https:\/\/www.europesays.com\/us\/wp-json\/wp\/v2\/media?parent=112098"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.europesays.com\/us\/wp-json\/wp\/v2\/categories?post=112098"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.europesays.com\/us\/wp-json\/wp\/v2\/tags?post=112098"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}