Tag

Oceanography

All articles tagged with #oceanography

physics-and-chemistry5 days ago•17 min saved

Whale Calls Debunk a Physics Paradox: It’s All About Wave Interference

An oceanographer noticed humpback calls near Massachusetts appeared to exceed the speed of sound, but the effect isn’t physics breaking — it comes from interference between the direct sound and its surface-reflected echo reaching the hydrophone, making the strongest signal peak appear to arrive faster. This observer-relative illusion aligns with special relativity concepts, and the researchers propose experiments to verify this underwater SR-like phenomenon, with potential applications to light-based tests.

via Gizmodo|

#acoustics #interference #oceanography

scienceoceanography11 days ago•13 min saved

A thousand deep-sea vehicles would still need centuries to map Earth's hidden ocean floor

New analysis of 43,681 dives (1958–2024) estimates the deep seabed (~335.7 million sq km) would require about 115,800 years to visually survey with 1,000 current-rate systems, meaning humans have directly seen less than 0.001% of the deep ocean. Mapping via multibeam sonar (about 28.7% mapped) is not equivalent to visual coverage, and observations are heavily biased toward a few countries and regions. The study advocates a strategic, globally representative sampling approach (Global Deep Sea Exploration Goals) and the use of smaller, longer-endurance vehicles and machine-assisted analysis to improve coverage much sooner, rather than pursuing an exhaustive camera sweep that would outlast civilizations.

via Space Daily|

#deep-sea #exploration #oceanography

science27 days ago•4 min saved

Hidden mantle on full display: oceanic core complexes rewrite the ocean floor story

Geologists once thought the ocean floor formed from steady upwelling magma that cools into basalt, but a 2009 high-resolution sonar survey revealed low-angle detachment faults that pull mantle rock up to the seafloor, creating oceanic core complexes. With more than 170 identified along slow-spreading ridges, these structures show mantle rock, not just crust, is exposed to seawater, triggering serpentinization and powering hydrothermal vents. The findings reframe crust formation, illuminate global geochemical cycles, and offer models for extraterrestrial oceans.

via futura-sciences.com|

#mantle-rock #oceanic-core-complexes #oceanography

science28 days ago•12 min saved

Earth’s ocean floor remains the least-charted giant landscape on the planet

Less than 30% of the world’s ocean floor is mapped to modern standards, while Mars and the Moon have globally detailed maps created with laser altimetry. Seawater absorbs measurement signals, so ship-based sonar remains the primary method for deep-sea mapping, leaving most of Earth’s largest landscape uncharted. The Seabed 2030 project and SWOT-derived data are gradually expanding coverage, but about 258 million square kilometres still lie outside the 28.7% currently charted, and progress depends on continued surveys and new data sources.

via Space Daily|

#bathymetry #gebco #oceanography

science-and-environment1 month ago•14 min saved

Deep-ocean turbulence could accelerate climate change within a lifetime

A Nature Communications study finds that tiny deep-ocean turbulence rapidly distributes heat, nutrients and carbon, influencing sea level rise and fisheries on decadal scales—far faster than current climate models capture. By tracing chlorofluorocarbons, researchers show deep waters move heat and carbon around on timescales relevant to human life, underscoring gaps in climate projections and the need for improved understanding and monitoring of small-scale ocean mixing to inform policy.

via Oceanographic Magazine|

#carbon-cycle #climate-change #deep-ocean-turbulence

science1 month ago•10 min saved

Earth’s Hidden Spine: The 65,000-Kilometer Undersea Mountain Chain

The mid-ocean ridge is the Earth’s longest mountain range, a 65,000‑km system of underwater volcanoes that encircles the globe and lies mostly beneath the sea. It forms where tectonic plates pull apart and new ocean crust is created. Mapped in the 1950s by Marie Tharp and colleagues, with major atlases published in 1957 and 1977, the ridge reshapes our view of the planet. Despite decades of sonar and satellite work, only about 28–29% of the seafloor has high‑resolution mapping as of 2026, and explorers have seen a vanishingly small fraction of the deep ocean floor, underscoring how much of Earth remains unseen.

via Space Daily|

#marie-tharp #mid-ocean-ridge #oceanography

science1 month ago•7 min saved

Four tech advances unlock the deep ocean's hidden frontiers

Scientists are unlocking the deep ocean with four key technologies: ocean-bottom seismometers mapping mantle convection; China’s Meng Xiang drilling ship to obtain pristine mantle samples; hydrophones enabling rapid, global tsunami prediction; and repurposed deep-sea cables transforming into a vast seismic surveillance network—together they aim to illuminate Earth’s mantle, plate tectonics and coastal hazards in a region still largely unmapped.

via Nature|

#deep-ocean #mantle #oceanography

science1 month ago•13 min saved

Seven Decades of Dives Yet Leaves Most Deep Seafloor Unseen

A Science Advances study compiling 43,681 submersible dives since 1958 finds humans have visually observed less than 0.001% of the deep seafloor, roughly the size of Rhode Island, with observations heavily concentrated near the US, Japan and New Zealand and most regions largely unsampled. The research emphasizes that close visual records complement maps but are uneven and sparse, highlighting the need for cheaper vehicles, shared archives, more open industrial imagery, and broader international participation to establish robust ecological baselines for biodiversity, climate, and resource decisions in the deep ocean.

via Space Daily|

#data-sharing #deep-sea #oceanography

environment1 month ago•21 min saved

Congo River Freshwater Plume Carried Offshore by Ocean Eddies

A study using observations and a 3-km ocean model shows the Congo River releases about 40,000 cubic meters of freshwater per second, creating a plume that reaches roughly 800 km offshore; during the wet season, mesoscale eddies trap and transport low-salinity water hundreds of kilometers away, with a notable 49-day anticyclonic eddy in 2016 driving offshore transport and affecting regional circulation and marine ecosystems.

via ZME Science|

#atlantic-ocean #congo-river #environment

science1 month ago•15 min saved

Patagonian Tides Reach Ice-Age Highs, Reshaping Carbon Storage

A study reconstructing 21,000 years of tidal change across the Patagonian Shelf finds tides are currently among the strongest since the end of the Ice Age, with shifts in shelf geometry linked to sea-level rise that affect sediment transport, coastal evolution, habitats, and the ocean’s capacity to store organic carbon.

via Oceanographic Magazine|

#carbon-storage #ice-age #oceanography

science2 months ago•3 min saved

Lost Undersea Probe Reveals Antarctic Ice Secrets

A 20-foot orange autonomous underwater vehicle named Ran explored the underside of West Antarctica's Dotson Ice Shelf in 2022, revealing a complex ice topography with terraces, channels, and teardrop pits unseen by satellites; when researchers returned in 2024 to monitor movement, Ran vanished without a trace, leaving researchers unsure of the cause but with valuable mapping data that show how warming Circumpolar Deep Water melts the shelf and could influence future sea-level rise.

via SlashGear|

#antarctica #dotson-ice-shelf #oceanography

environment2 months ago•35 min saved

Humans behind Atlantic warming, upending natural-cycle theory

New research shows Atlantic Ocean warming is driven by human activity—greenhouse gases warming the surface and aerosols reflecting sunlight—rather than natural ocean cycles; using rotated low-frequency component analysis on data from 1920–2025, scientists separate human- and natural signals, with implications for hurricane trends and coastal planning, while the Pacific remains dominated by natural variability.

via Earth.com|

#anthropogenic-emissions #atlantic-ocean-warming #climate-change

science2 months ago•10 min saved

Underwater Waterfall in Denmark Strait Drops 3,500 Meters, Driving Atlantic Circulation

The Denmark Strait cataract is the world’s largest waterfall, an underwater, density-driven flow where cold Nordic seawater plunges about 3,500 meters down a deep seabed, moving roughly 3.5 million cubic meters per second across a ~480 km-wide slope and shaping the Atlantic’s deep circulation.

via Space Daily|

#atlantic-meridional-overturning-circulation #deep-ocean-circulation #denmark-strait-cataract

science2 months ago•4 min saved

Robotic Sub Uncovers Rugged Underbelly of Dotson Ice Shelf

A Swedish autonomous underwater vehicle named Ran mapped the Dotson Ice Shelf’s hidden underside, revealing a complex landscape of terraces, channels and teardrop-shaped cavities carved by ocean currents. The 2022 mission covered about 55 square miles across roughly 1,000 km in 27 days, providing the first high-resolution view of the ice shelf’s base. Ran disappeared on a 2024 follow-up dive, but the data show melting beneath Antarctica is more intricate than models predict, with implications for ice-shelf stability and potential sea-level rise.

via The Times of India|

#antarctica #dotson-ice-shelf #oceanography

climate2 months ago•185 min saved

Trump Admin Dismantles Vital Deep-Ocean Monitoring Network

The Trump administration will dismantle the Ocean Observatories Initiative, a $368 million deep-ocean monitoring network with about 900 instruments across the Pacific and Atlantic, removing in-water infrastructure over 15 months. Scientists warn the move could hamper fisheries management, weather forecasting, and understanding the Atlantic Meridional Overturning Circulation amid record ocean warming and an impending El Niño.

via CNN|

#amoc #climate #nsf