Tag

Oceanography

All articles tagged with #oceanography

science8 days ago•5 min saved

Hidden Ocean Brakes Limit Earthquakes on a Pacific Transform Fault

Scientists studying the Gofar transform fault off Ecuador found fractured, seawater-filled rock zones that act as dynamic brakes, repeatedly limiting ruptures to around magnitude 6 with a remarkably regular cycle. Seafloor sensors deployed in 2008 and again from 2019–2022 recorded bursts of small quakes in barrier regions before major ruptures and quiescence afterward, consistent with a dilatancy-strengthening mechanism driven by trapped fluids. The study suggests such barrier zones actively control rupture propagation on oceanic transform faults and could inform broader models of underwater earthquakes, though these faults lie far from shore communities.

via The Daily Galaxy|

#dilatancy-strengthening #earthquakes #gofar-fault

science10 days ago•4 min saved

Giant East Coast Algal Bloom Visible From Space, NASA Reports

NASA satellites have detected a massive blue-green algal bloom along the U.S. East Coast (New Jersey to Virginia) that has grown since mid-April and is visible from space. The bloom is driven by river outflows, spring storms, and dense phytoplankton populations, and scientists are using MODIS imagery and the PACE mission to monitor its composition and spread. There are no signs of toxicity at present, and experts expect the bloom to fade in coming weeks unless nutrients persist.

via The Daily Galaxy|

#algal-bloom #modis #nasa

science11 days ago•92 min saved

Antarctica’s sea-ice melt: winds and deep heat rewrite the southern ocean story

A Science Advances study traces Antarctica’s sudden sea-ice collapse from 2013–2023 to a three-stage sequence in which stronger westerly winds first slosh cold, fresh surface waters away and uncover a deeper warm, salty layer, then mix that heat upward after 2015, and finally trigger self-reinforcing feedbacks that thin and delay sea-ice formation. The result has driven record-low sea-ice extent in 2023 and below-average extents in 2024–26, while threatening the Southern Ocean’s heat and carbon storage and disrupting ecosystems. Although the system has shifted to a new regime, scientists say a full collapse hasn’t occurred yet and future changes (like precipitation or glacier melt) could alter the trajectory.

via Live Science|

#antarctica #climate-change #oceanography

science17 days ago•5 min saved

Arctic Ocean’s Hidden Waterfall Is Earth’s Largest by Volume

NOAA-backed research reveals the Denmark Strait cataract, an underwater waterfall beneath the Arctic between Iceland and Greenland, draining cold Nordic Sea water downward at about 3.2 million cubic meters per second (≈123 million cubic feet per second). It’s the world’s largest waterfall by volume, though invisible to ships, and it helps drive the Atlantic Meridional Overturning Circulation, influencing Europe’s climate and marine ecosystems. Warming could weaken or alter this flow, with potential global climate implications.

via Indian Defence Review|

#amoc #arctic #climate

science19 days ago•5 min saved

Antarctica’s Ice Melt Mystery: Submarine Ran Returns with Data That Upends Climate Models

An autonomous submarine named Ran vanished under Antarctica’s Dotson Ice Shelf in January 2024 after 14 successful missions mapping about 130 square kilometers; though lost, the data it collected revealed unexpected ice–ocean features and erosion patterns that challenge current melt models, with the western part melting faster due to turbulent waters. Researchers at ITGC plan to replace Ran with Ran II to continue the mission, and the findings were published in Science Advances, potentially reshaping predictions of sea‑level rise.

via The Daily Galaxy|

#antarctica #climate-change #dotson-ice-shelf

science23 days ago•7 min saved

SWOT Satellite Reveals New Dispersive Dynamics in a Pacific Tsunami

NASA’s SWOT satellite captured the first high-resolution, wide-area view of a Pacific tsunami from the Kamchatka quake, revealing dispersive wave energy and complex interactions not predicted by classic non-dispersive models. By combining SWOT data with DART buoy measurements, researchers refined the rupture length to about 400 km and highlighted the potential for smarter, faster tsunami forecasting, though real-time use remains a challenge.

via Indian Defence Review|

#forecasting #nasa #oceanography

science24 days ago•10 min saved

SWOT Satellite Reveals Dispersive Tsunami Patterns Across the Pacific

NASA’s SWOT satellite captured the first high-resolution, space-based track of a major Pacific tsunami from the Kuril–Kamchatka earthquake, revealing dispersive wave energy across a wide swath and challenging the traditional view that giant tsunamis travel as a single non-dispersive wave. By combining SWOT data with DART buoy measurements, researchers refined the earthquake’s source and suggested a longer southward rupture, with implications for improving real-time tsunami forecasting.

via SciTechDaily|

#earthquakes #oceanography #satellite

science1 month ago•3 min saved

Atlantic Conveyor Could Slow by Half by 2100, New Study Finds

A new Science Advances study using observational constraints projects the Atlantic Meridional Overturning Circulation could weaken about 50% by 2100 (with 90% probability), a pace and magnitude stronger than many climate models, raising concerns it could approach a tipping point with widespread climatic consequences such as sea-level rise along coastlines and shifts in storms and rainfall.

via Gizmodo|

#amoc #atlantic-ocean #climate-change

science1 month ago•18 min saved

SWOT Satellite Reveals Braided Pacific Tsunami and Forecast Implications

The SWOT satellite captured the first high-resolution, spaceborne swath of a Pacific-wide tsunami triggered by the 2025 Kuril–Kamchatka quake, revealing a braided energy pattern and dispersive waves that challenge traditional non-dispersive tsunami models; by combining SWOT data with DART sensors and seismic records, scientists revised the rupture length and underscored the need to merge multiple data streams for more accurate near-real-time tsunami forecasting.

via Earth.com|

#forecasting #oceanography #satellite

science1 month ago•4 min saved

Ten-kilometer fiber-optic cable reveals 56,000 glacier calving events beneath Greenland’s fjords

Researchers laid a 10-km fiber-optic cable on the seafloor near a Greenland glacier and used distributed acoustic and temperature sensing to monitor calving. Over three weeks the system recorded more than 56,000 iceberg detachments, uncovering the full calving sequence from internal cracking to detachment and underwater waves, and revealing how iceberg motion drives water circulation and heat distribution. This continuously sensing approach provides high-resolution insights into glacier dynamics and ocean interactions that aren’t captured by surface observations.

via The Daily Galaxy|

#distributed-acoustic-sensing #fiber-optic-sensing #glacier-calving

environment1 month ago•18 min saved

Ran Submarine Uncovers Hidden Under-Ice Structures Beneath Dotson Shelf, Then Goes Silent

An autonomous submarine named Ran mapped roughly 54 square miles of the underside of Dotson Ice Shelf in West Antarctica, revealing terraces, teardrop pits, and fractures carved by basal melt, before going silent about ten miles under the shelf. Led by Anna Wåhlin of the University of Gothenburg, Ran’s under-ice maps show how warm Circumpolar Deep Water melts ice from below and concentrates erosion on the western side, with implications for future sea-level rise. The mission, conducted in 2022 and reported in Science Advances, underscores how hidden melt machinery challenges current models while leaving Ran’s fate undetermined.

via Earth.com|

#antarctica #dotson-ice-shelf #environment

science1 month ago•5 min saved

Winds and continental drift unlocked the Antarctic Circumpolar Current

New simulations show the Antarctic Circumpolar Current formed around 34 million years ago only after Australia moved north and strong westerlies blew through the Tasman Gateway, aided by a CO2 drop from ~1,000 to ~600 ppm and Antarctic isolation. Once fully developed, the ACC helped stabilize global climate by linking ocean basins and keeping warmer waters away from the ice sheets. Today, climate warming may push the current southward and slow it by about 20% by 2050, risking biodiversity and ice-sheet stability.

via ScienceAlert|

#antarctic-circumpolar-current #climate-change #oceanography

science2 months ago•6 min saved

NASA’s SWOT Reveals Hidden Ocean Floor in Unprecedented Global Map

NASA's SWOT satellite has produced a high-resolution, global map of the seafloor by measuring subtle sea-surface height variations, revealing features like abyssal hills and tectonic structures that were previously hidden from space. This breakthrough accelerates ocean science, improves models of ocean circulation and climate, and has implications for resource management, shipping, hazard detection, and national security. The effort aims to complete a comprehensive global seafloor map by 2030, blending space-based observations with traditional ship-based mapping.

via Indian Defence Review|

#abyssal-hills #oceanography #satellite-remote-sensing

science2 months ago•3 min saved

NASA’s SWOT Satellite Maps the Ocean Floor From Space

NASA and CNES’s SWOT satellite uses gravity-driven sea-surface height data to map the seafloor, enabling detection of smaller features like seamounts and abyssal hills and potentially expanding the catalog from about 44,000 to up to 100,000. The effort aims to map the entire ocean floor by 2030, complementing ship-based sonar with near-global coverage every 21 days.

via BBC Sky at Night Magazine|

#nasa #oceanography #satellite

science2 months ago•4 min saved

Gigantic Subsea Waves Behind Greenland Melt Accelerate Glacier Loss

Researchers deployed a 10-km fiber-optic cable to monitor a Greenland glacier and detected massive underwater waves generated by iceberg calving. These internal waves keep warm seawater in contact with the glacier base, creating a calving multiplier that speeds up melt and could amplify ice loss and influence ocean circulation.

via The Daily Galaxy|

#climate-change #glaciology #greenland