{"id":530686,"date":"2026-04-14T17:51:09","date_gmt":"2026-04-14T17:51:09","guid":{"rendered":"https:\/\/www.newsbeep.com\/uk\/530686\/"},"modified":"2026-04-14T17:51:09","modified_gmt":"2026-04-14T17:51:09","slug":"scientists-dropped-a-10-kilometer-underwater-cable-and-it-detected-56000-hidden-events-beneath-glaciers","status":"publish","type":"post","link":"https:\/\/www.newsbeep.com\/uk\/530686\/","title":{"rendered":"Scientists Dropped a 10-Kilometer Underwater Cable and It Detected 56,000 Hidden Events Beneath Glaciers"},"content":{"rendered":"

A fiber-optic cable lying quietly on the seafloor has captured 56,000 iceberg break-offs in just three weeks. This experiment reveals, in remarkable detail, how glaciers fracture, collapse, and reshape the ocean around them. Glacial calving, the process by which icebergs detach from a glacier, is one of the most visible signs of change in polar regions. <\/p>\n

Along Greenland\u2019s coast, these events occur constantly, from small fragments to massive ice blocks plunging into the sea. Much of the activity happens below the surface and remains poorly understood. Researchers have long struggled to observe what happens at a glacier\u2019s submerged front. Remote sensing captures only what rises above the waterline, leaving a major gap.<\/p>\n

Fiber-Optic Breakthrough Beneath a Fjord<\/p>\n

To address this challenge, a team led by Dominik Gr\u00e4ff <\/a>from the University of Washington deployed a 10-kilometer fiber-optic cable across a fjord in southern Greenland, near the Eqalorutsit Kangilliit Sermiat (EKaS) glacier. According to a study published in Nature<\/a>, positioned about 500 meters from the glacier\u2019s front, the cable transformed the seafloor into a continuous sensing system. <\/p>\n

\"GlacierGlacier calving diagram with fiber-optic sensing on the seafloor. Credit: Nature<\/p>\n

The operation required careful navigation through dense ice m\u00e9lange, a shifting mix of sea ice and icebergs that can quickly close in behind a vessel. Gr\u00e4ff explained that:<\/p>\n

\u201cIf you go too slow, the ice m\u00e9lange that you push open with your vessel [will close] quickly, And that prevents your cable from sinking down.\u201d<\/p>\n

Once installed, the system relied on distributed acoustic sensing (DAS)<\/a> and distributed temperature sensing (DTS)<\/a>. Laser pulses sent through the fiber detected vibrations and temperature changes along its entire length. As explained, this technique made it possible to track events lasting only milliseconds.<\/p>\n

56,000 Events Uncover Full Calving Sequence<\/p>\n

Over a three-week period, the cable recorded more than 56,000 iceberg detachments, providing a continuous record of calving activity. This volume of data is rarely achieved in glaciology.<\/p>\n

The observations revealed a clear sequence. It begins with internal cracking within the glacier, producing acoustic signals that travel through the fjord. These are followed by the detachment of ice, which generates underwater waves<\/a> and pressure changes detectable along the cable.<\/p>\n

Some events triggered small, localized tsunamis<\/a>, while others produced more subtle disturbances. The system also detected the sounds of icebergs breaking apart after entering the water. These signals resemble the initial cracking phase but originate within the fjord.<\/p>\n

\"DasDAS signals capturing glacier calving wave patterns. Credit: Nature<\/p>\n

According to seismologist Andreas Fichtner<\/a> of ETH Z\u00fcrich, capturing so many different physical processes in such a short time is unusual. He noted that:<\/p>\n

\u201cThere are very few seismological datasets where, within such a short amount of time, you record so many different phenomena.\u201d<\/p>\n

Underwater Dynamics Finally Revealed<\/p>\n

Beyond the visible break-offs, the cable revealed complex water movements that are rarely observed directly. Among them were internal gravity waves, which travel along the boundary between cold freshwater from melting ice and warmer saltwater below.<\/p>\n

As icebergs drift<\/a> away from the glacier, they generate wakes that stir these layered waters. This movement affects how heat is distributed in the fjord and influences how quickly submerged ice melts. As reported by EOS Magazine<\/a>, the cable\u2019s temperature measurements captured these subtle changes in real time.<\/p>\n

Researchers also observed how iceberg motion drives circulation patterns, adding another layer to the calving process. These interactions between ice and ocean are often missing from existing models.<\/p>\n

\"InIn southern Greenland, Dominik Gr\u00e4ff (left) and a crew member work near the EKaS glacier as the vessel Adolf Jensen stands nearby. Credit: Julia Schmale.<\/p>\n","protected":false},"excerpt":{"rendered":"A fiber-optic cable lying quietly on the seafloor has captured 56,000 iceberg break-offs in just three weeks. This…\n","protected":false},"author":2,"featured_media":530687,"comment_status":"","ping_status":"","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[7],"tags":[59,90,56,54,55],"class_list":{"0":"post-530686","1":"post","2":"type-post","3":"status-publish","4":"format-standard","5":"has-post-thumbnail","7":"category-science","8":"tag-gb","9":"tag-science","10":"tag-uk","11":"tag-united-kingdom","12":"tag-unitedkingdom"},"_links":{"self":[{"href":"https:\/\/www.newsbeep.com\/uk\/wp-json\/wp\/v2\/posts\/530686","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.newsbeep.com\/uk\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.newsbeep.com\/uk\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.newsbeep.com\/uk\/wp-json\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/www.newsbeep.com\/uk\/wp-json\/wp\/v2\/comments?post=530686"}],"version-history":[{"count":0,"href":"https:\/\/www.newsbeep.com\/uk\/wp-json\/wp\/v2\/posts\/530686\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.newsbeep.com\/uk\/wp-json\/wp\/v2\/media\/530687"}],"wp:attachment":[{"href":"https:\/\/www.newsbeep.com\/uk\/wp-json\/wp\/v2\/media?parent=530686"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.newsbeep.com\/uk\/wp-json\/wp\/v2\/categories?post=530686"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.newsbeep.com\/uk\/wp-json\/wp\/v2\/tags?post=530686"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}