Astronomer Angelo Secchi demonstrates the Secchi disk, which measures water clarity, aboard Pope Pius IX's yacht, the L'Immaculata Concezion.
It is a plain white, circular disk 30 cm in diameter used to measure water transparency or turbidity in bodies of water. The disc is mounted on a pole or line and lowered slowly down in the water. The depth at which the disk is no longer visible is taken as a measure of the transparency of the water (Secchi depth).
Today, learn about the 32 U.S coastal cities, affecting up to 500,000 people, that are at an increased risk of experiencing one or more major flooding events in the next twenty years, due to land subsidence and sea-level rise. https://news.vt.edu/articles/2024/01/research-sinkingcoasts.html
Crabs, kelp and mussels: Argentina’s waters teem with life – could a fish farm ban do the same for Chile?
While the ecosystem is thriving off the coast of Argentina, the proliferation of salmon farms in Chile’s waters is threatening marine life, say critics
Weekend #Plankton#Factoid 🦐🦠
The ubiquitous tool of #zooplankton#science is the Plankton Net. The first documented use was by British surgeon Dr John Vaughan Thompson to catch the brightly coloured copepods Sapphirina and barnacle larvae. Darwin brought these nets on the HMS Beagle. Originally fine muslin, then silk, now are highly accurate sized meshes of nylon. Modern quantitative #oceanography nets with removable cod-end have been standardized since late 1800s and named for Victor Hensen.
Is the Atlantic Overturning Circulation Approaching a #TippingPoint?
Studies show that the Atlantic Meridional Overturning Circulation (#AMOC) has already weakened as a result of anthropogenic #ClimateChange and is possible moving towards a tipping point. This current has a significant influence on #climate, particularly in #Europe.
Swiss scientist Alexander Agassiz died #OTD in 1910.
He assisted Charles Wyville Thomson in the examination & classification of the collections of the 1872 Challenger Expedition, and wrote the Review of the Echini (2 vols., 1872–1874) in the reports. Agassiz's legacy lies in his contributions to marine science & geology particularly his studies on coral reefs and his efforts to advance the field of oceanography.
did a radio podcast thing for our #Antarctic voyage - it was a great conversation (Sharon Brettkelly was so on to it) but I rambled as usual - the team at Radio NZ crafted a great (and dare I say important) story. And our PhD student Liv just aced it with enthusiasm to counter my school principal vibe. #DoYourSelfaFavour#climate#oceanography#polynya
Most northern known’ coral reef off B.C. coast shouldn’t exist: expert
The Fisheries Department announced last week it had closed the area on B.C.’s central coast over the coral reef to all commercial and recreational bottom-contact fisheries, including mid-water trawl.
We use a variety of intelligence-led enforcement methods including air, ocean, river, and ground surveillance,...”
Can Marine Mammals and Munitions Coexist?
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As the humpback whale population rebounds in an area of the Salish Sea used for military weapons training, scientists raise concerns.
Scottish natural historian & marine zoologist Charles Wyville Thomson was born #OTD in 1830. Being interested in crinoids, he used of HMS Lightning and HMS Porcupine for deep sea dredging expeditions in the summers of 1868 & 1869. They showed that animal life existed down to depths of 1200 m, that all marine invertebrate groups are present at this depth, & that deep-sea temperatures are not as constant as had been supposed, but vary considerably, and indicate oceanic circulation.
Reasonably accurate representation… the close metal ship is in sharp focus and the world outside is ever so slightly blurry… just left the 60S #oceanography
Well it’s time to head north - and as we do it has decided to snow so our little icebreaker looks like (northern hemisphere) Christmas .. likely no more sea ice or bergs … we likely have some proper waves ahead for the 6 day transit… although there is a path through the waves #Antarctica#Climate#Oceanography
This is an oceanographic phenomenon worthy of our attention and alarm. Lots of talk about #TippingPoint events lately, with good reason. This is one of the most important to track, with profound global implications for #ClimateChange and #ExtinctionEvent triggering. If the #AMOC becomes more unstable, as it is doing every year, it WILL collapse - within a few generations. And that, my friends, will change the world in dramatic ways. We don’t want to go there, but are well on our way. #Oceans#Oceanography#AtlanticCurrents#ClimateCrisis#ClimateEmergency
Highly recommend “At Every Depth” (coauthored by my good friend Eric Simons). It’s a new book about the impact of #climate change on the oceans that braids together indigenous knowledge with the latest science on a whole range of ecosystems, from tide pools to the deep sea. Full of great storytelling and writerly prose that’ll make it just as readable and compelling for casual readers as for scientists and climate activists.
implausibly real... layer cake of #Antarctic cloud, Victoria Land mountains (some being 4 km high) and an ocean right at the point of #seaice forming... we slowly drifted up to it before starting a sampling line moving up the coast. #oceanography#cold
a few days back I was in my cabin on an icebreaker rambling over WhatsApp to a reporter and she made something coherent emerge.
here's something beyond the incomprehensibly beautiful scenes we've had the privilege to witness #climate#oceanography#Antarctica#SeaIce
#Antarctic update... ship has wedged itself into pack ice in order to damp out waves as we prepare to ride out next storm. The angle of this one leaves us with nowhere to hide. The sky is so dark partly because there is open water a little distance away #oceanography#polar#icebreaker