Oceans

ocean

Ancient wildfires suggest rising atmospheric oxygen helped end past ocean anoxia

Many times throughout Earth’s history, oxygen levels in the world’s oceans have decreased dramatically in episodes called oceanic anoxic events (OAEs), which have caused massive marine die-offs. In the Early Jurassic, for example, the Toarcian OAE has been linked with the extinction of many ammonite species and other sea life. However, how such episodes end remains largely unclear to scientists.

22 Aug 2017

A new — and more toxic — normal? Harmful algal blooms find new habitats in changing oceans

A massive and deadly algal bloom along the West Coast of North America in 2015 is just one example of the growing number of severe algal blooms that are occurring throughout the world's oceans. Scientists are studying how toxic species are adjusting to a warming climate. 

16 Jan 2017

Pluto may still have liquid ocean

Last year, images from NASA’s New Horizons flyby of Pluto revealed geologic activity that suggested a liquid ocean may have once lurked beneath the dwarf planet’s icy crust. But whether it still exists in that state, or had frozen, remained a question. According to a new study published in Geophysical Research Letters, it may still be partially liquid.

14 Nov 2016

Drilling for gold inside a submarine volcano

Earth scientists have been given the green light to drill into an active submarine volcano for the first time, with the hope of discovering substantial new reserves of valuable metals, as well as new forms of extreme life.

31 Oct 2016

Tiny ocean bacteria could play big role in climate

In the 1990s, researchers identified the most abundant group of organisms in the ocean as Pelagibacterales, a class of free-living bacteria that live in surface waters as a microscopic but major part of the phytoplankton community. Now, a new study suggests that Pelagibacterales could play an important role in the global climate cycle by producing dimethylsulfide (DMS), an organosulfur compound that stimulates cloud formation when it gets into the atmosphere.

05 Sep 2016

The softer side of hydrothermal vents

Seafloor chimneys belching dark plumes of superheated, acidic fluids into the ocean, called “black smokers,” are the most common kind of submarine hydrothermal vent known. But recently scientists discovered a vent system, of a seemingly gentler nature, unlike any observed before.

21 Apr 2016

North Sea uplift caused Jurassic cooling event

The climate of the Jurassic, long envisioned as ubiquitously warm from the equator to the poles, was actually more dynamic, sometimes cooling dramatically, according to a new study. The research joined isotopic and sedimentological data to suggest that an abrupt cooling event occurred in the midlatitudes early in the Middle Jurassic as a result of changing ocean currents associated with a feature known as the North Sea Dome.

31 Mar 2016

No laughing matter: Ocean nitrous oxide emissions greater than thought

Nitrous oxide is a potent greenhouse gas and, since the banning of chlorofluorocarbons in 1987, it has become the main driver of ozone loss from the stratosphere. Most atmospheric nitrous oxide is emitted from agricultural land and soils, but roughly a third is thought to come from the ocean. However, marine sources and sinks of the gas are not well understood. 
 
27 Nov 2015

Enceladus' extremely alkaline underground ocean

Saturn’s moon Enceladus is home to a vast underground ocean that erupts to the surface at the moon’s south pole in a giant plume of gas, ice and dust. Scientists studying observational data of this plume collected by the Cassini spacecraft, which has been orbiting Saturn since 2004, have recently learned more about the chemistry of Enceladus’ hidden ocean. 
 
24 Nov 2015

Ancient asteroids boiled Earth's oceans

The asteroid that wiped out the remaining dinosaurs — save for the avian variety — 66 million years ago was roughly 10 kilometers wide. Long before that, however, early Earth was bombarded by many larger impactors, which pulverized Earth’s surface time and again. Now, a new study published in Geology suggests that two asteroids, dating to Archean times and estimated to be 50 to 100 kilometers in diameter, released enough energy to boil the oceans and reduce sea level by as much as 100 meters or more.
 
10 Oct 2015

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