Ocean on EARTH Magazine

Down to Earth With: Coastal scientist Gary Griggs

Thu, 08 Nov 2018 09:27:50 -0500

Coastal scientist Gary Griggs has been teaching at the University of California, Santa Cruz, for the past 50 years. An advocate for ocean science, conservation, policy and education, he has studied coasts around the world, including the beach pictured here, Coral Beach on the Isle of Skye, Scotland. Credit: courtesy of Gary Griggs.

Maybe it was the summer camping trips with his family along the Pacific coast, or perhaps surfing off Santa Barbara, Calif., during college, but Gary Griggs always gravitated to the ocean. He turned that love into a career and has spent the last 50 years teaching about the oceans and coasts at the University of California, Santa Cruz (UCSC).

Surfactants slow oceanic carbon dioxide uptake

Mon, 10 Sep 2018 11:28:54 -0400

Across the Atlantic Ocean, researches sampled the surfactant layer across several sites. Credit: Michael A. Orlando, CC BY-SA 3.0

The oceans are the largest long-term carbon sink on Earth, absorbing about a quarter of all anthropogenic carbon dioxide emissions. The rate of exchange of carbon dioxide between the oceans and the atmosphere is thought to be primarily controlled by wind-driven turbulence at the sea surface. More turbulence leads to increasing gas exchange and higher rates of carbon uptake by the ocean. But in a new study, published in Nature Geoscience, scientists found that biomolecules called surfactants floating at the sea surface may significantly reduce carbon dioxide exchange with the atmosphere — reducing the uptake of carbon dioxide by up to 50 percent. “As surface temperatures rise, so too do surfactants, which is why this is such a critical finding,” said lead author Ryan Pereira of Heriot-Watt University in Scotland in a statement.

Radium levels suggest Arctic Ocean chemistry is changing

Tue, 10 Apr 2018 11:44:26 -0400

In 2015, researchers measured radium in the Arctic Ocean from the Chukchi Shelf (where the voyage started) to the North Pole. Elevated radium levels (shown in bright yellow along the cruise route) were found near the North Pole, possibly as a result of transport from the East Siberian Arctic Shelf. Credit: Natalie Renier, Woods Hole Oceanographic Institution.

Rising temperatures have already caused changes in the Arctic environment, like diminishing sea ice and thawing permafrost. Now, it appears that sea-ice loss could be throwing Arctic Ocean chemistry out of whack.

Gyres spin up, currents get muddled

Thu, 08 Mar 2018 11:37:13 -0500

In the Weddell Sea Gyre, one of two clockwise-spinning circulation patterns in the Southern Ocean, warming has accelerated the spinning. Recent research suggests this acceleration — and the warmer, faster-moving Antarctic Circumpolar Currrent and Circumpolar Deepwater that result — may trigger the development of smaller, shorter-lived polynyas like those observed over the past two years. Credit: K. Cantner, AGI.

In addition to polynya formation and warming-induced surface freshening, other factors may also impact open-ocean convection in the Southern Ocean. The warming atmosphere is shifting global climatic zones and their associated wind fields poleward in both hemispheres. In the Weddell Sea Gyre, one of two clockwise-spinning circulation patterns in the Southern Ocean, this shift has resulted in a dramatic increase in wind stress curl (the strength of the wind’s influence on ocean water flow) over the past two years.

Disrupting the deep: Ocean warming reaches the abyss

Thu, 08 Mar 2018 11:29:52 -0500

SOCCUM Project, Hannah Zanowski, CC BY 2.0

Seventy-one percent of our planet is covered by ocean, and these basins contain 97 percent of Earth’s near-surface water. The ocean lies at the heart of the global climate system, shaping all parts of our environment, even in the deepest continental interiors. So as the ocean goes, so goes the planet — and the ocean is warming.

Heating up Enceladus' ice-covered ocean

Tue, 27 Feb 2018 13:20:21 -0500

Friction produced by tidal forces acting on Enceladus' highly fragmented, porous core could produce enough heat to sustain the moon's liquid ocean. Credit: NASA/JPL-Caltech.

Saturn’s sixth-largest moon, Enceladus, is covered by ice, but just beneath its icy surface lies an ocean of liquid water. New research suggests that this internal ocean may be maintained in a liquid state by heat generated by tidal friction within the moon’s fragmented, rocky core.

Driftwood reveals ancient Arctic currents and sea-ice levels

Thu, 28 Dec 2017 12:37:35 -0500

Driftwood frozen into sea ice can be transported around the Arctic, eventually collecting on distant shores such as on the island of Phippsøya in Svalbard, which lies to the east of northern Greenland. Credit: Marc Macias-Fauria

Arctic driftwood up to 12,000 years old is giving scientists a better understanding of how ocean currents and sea ice in the far north have changed through the Holocene. In a new study, published in the Journal of Geophysical Research: Oceans, scientists at the University of Oxford in England studied more than 900 pieces of driftwood collected from Arctic shorelines since the 1950s to investigate how shifting Arctic Ocean currents help melt or fortify sea ice.

Ancient wildfires suggest rising atmospheric oxygen helped end past ocean anoxia

Thu, 17 Aug 2017 17:15:07 -0400

Rising atmospheric oxygen levels may have spurred wildfire activity and helped bring an end to a bout of ocean anoxia about 180 million years ago. Credit: Chuck Hanlon, South Florida Water Management District, CC BY 2.0

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.

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

Fri, 13 Jan 2017 13:06:09 -0500

An Envisat image of a phytoplankton bloom in the South Atlantic Ocean east of the Falkland Islands on Dec. 2, 2011. Chlorophyll pigment detected by ocean-color sensors on Earth-observing satellites can help identify species in algal blooms and their toxicity. Credit: ESA.

In May 2015, a seizure-wracked sea lion hauled itself ashore on a beach in southern Washington. Testing confirmed it was suffering from domoic acid poisoning, an illness that causes disorientation, seizures and sometimes death that stems from the consumption of fish or shellfish contaminated by a toxic species of algae called Pseudo-nitzschia. To the south, in warm California waters where localized toxic blooms of Pseudo-nitzschia are a near-annual occurrence, sea lion illnesses caused by exposure to domoic acid are common — however, this was a first in Washington. The sick sea lion was euthanized, but its stranding in Washington alerted coastal communities to the massive algae bloom that was engulfing coastal waters from Santa Barbara, Calif., all the way to British Columbia.

Pluto may still have liquid ocean

Wed, 19 Oct 2016 16:29:01 -0400

Deep fractures revealing tectonic activity suggests that Pluto may have a liquid ocean. Credit: Credit: NASA/JHUAPL/SwRI.

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.

Tiny ocean bacteria could play big role in climate

Tue, 16 Aug 2016 16:36:11 -0400

Stephen Giovannoni's team samples for Pelagibacterales off Bermuda. Credit: Ben Temperton.

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.

Drilling for gold inside a submarine volcano

Thu, 14 Jul 2016 15:12:35 -0400

In 2018, researchers aboard International Ocean Discovery Program's JOIDES Resolution ship will drill into an active submarine volcano — Brothers Volcano, part of the Kermadec Arc north of New Zealand — for the first time. Credit: William Crawford, IODP JRSO/TAMU

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.

Benchmarks: March 1961: Project Mohole undertakes the first deep-ocean drilling

Wed, 06 Jul 2016 13:15:34 -0400

Early near-shore trials of the CUSS I drillship occurred off La Jolla, Calif., where the writer John Steinbeck noted that the barge, with its drilling derrick rising amidship, had the "sleek race lines of an outhouse standing on a garbage scow." Credit: Willard Bascom, National Academy of Sciences.

Since its inception in the 1960s, the ocean drilling program — an international research program that explores the world’s ocean basins — has logged hundreds of thousands of hours of ship time traveling the world’s oceans, drilling boreholes and retrieving cores of sediment and rock that have revealed Earth’s deep history and structure.

Benchmarks: January 23, 1960: Humans reach the deepest point on Earth

Mon, 20 Jun 2016 14:40:15 -0400

Jacques Piccard and Don Walsh in the crew cabin as the Trieste descends to Challenger Deep. Credit: NOAA.

More than 9,000 meters underwater, a window buckles, sending a spider web of cracks across the glass. The entire submersible shakes, but no water rushes into the Trieste. Out of vocal contact with the main ship on the surface above them, Swiss oceanographer and engineer Jacques Piccard and U.S. Navy Lt. Don Walsh decide to continue their descent despite the new danger. After all, at more than nine kilometers below the sea surface, the explorers were too close to their goal to turn around. They were only 2,000 meters away from the deepest spot on Earth: Challenger Deep. On Jan. 23, 1960, they reached that fabled point 10,916 meters below the surface of the Pacific Ocean.

The softer side of hydrothermal vents

Tue, 19 Apr 2016 15:34:36 -0400

A 3-meter-tall talc spire tops the main hydrothermal vent in the Von Damm Vent Field. Credit: National Oceanography Center Southampton.

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.

North Sea uplift caused Jurassic cooling event

Wed, 30 Mar 2016 19:02:35 -0400

The Laurasian Seaway (a) connected the Boreal Sea to the Tethys Ocean to the south during the Jurassic. Uplift of the North Sea Dome (b) beginning in the Early Jurassic might have blocked the northward flow of warm Tethyan waters through the seaway, causing an abrupt cooling event about 174 million years ago. Credit: Korte et al., Nature Communications, December 2015, CC BY 4.0.

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.

No laughing matter: Ocean nitrous oxide emissions greater than thought

Thu, 12 Nov 2015 08:46:09 -0500

High productivity ecosystems like the upwelling zone off the coast of Peru, which once supported an abundant anchovy fishery before overfishing collapsed it in the 1970s and ‘80s, also create oxygen minimum zones where high fluxes of nitrous oxide are produced. Credit: ©Shutterstock.com/Sven Schermer.

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.

Enceladus' extremely alkaline underground ocean

Mon, 02 Nov 2015 11:58:47 -0500

A diagram illustrating the possible interior of Saturn's moon Enceladus, including the ocean and plumes in the south polar region. Credit: NASA/JPL-Caltech.

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.

Ancient asteroids boiled Earth's oceans

Mon, 21 Sep 2015 11:28:06 -0400

Donald Lowe and Gary Byerly examine Archean rocks that preserve evidence of impacts in South Africa. Credit: Donald Lowe.

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.

Southbound icebergs off the hook for ice-age cooling

Fri, 17 Jul 2015 09:27:00 -0400

A new study suggests that southbound icebergs probably arrived too late to be the trigger for Pleistocene cooling events in the North Atlantic. Credit: ©kaet44, CC BY 2.0.

During the Late Pleistocene, changes in North Atlantic Ocean circulation triggered abrupt changes in global climate: In some locations in the Northern Hemisphere, average temperatures dropped by as much as 10 degrees Celsius within a few decades. Scientists have long thought that freshwater from melting icebergs traveling south from the Arctic may have instigated the circulation shifts that contributed to cooling feedback loops. But now, scientists looking at seafloor sediments collected near Iceland have found that pulses of icebergs typically arrived after the onset of cooling episodes, too late to be primary drivers of climate change.

A pair of moons with underground oceans

Mon, 06 Jul 2015 13:34:09 -0400

Interactions between deep ocean water and hot rock on Saturn's moon Enceladus are thought to result in hydrothermal plumes that erupt through the moon's icy crust. Credit: NASA/JPL-Caltech.

Jupiter and Saturn are both gas giants boasting multiple moons. Now, two separate studies have identified another similarity: Each appears to have a moon with hidden underground oceans.

Some coral reefs bounce back after bleaching

Wed, 08 Apr 2015 15:34:56 -0400

This recovering coral reef in the Seychelles is dominated by structurally complex Acropora and Porites corals, which provide shelter for fish and other organisms. Credit: Nicholas Graham

Ocean temperatures that rise too much or for too long can harm coral reefs, sometimes causing mass die-offs that leave reefs nearly barren of live corals. But scientists don’t know if or under what conditions reefs — which provide habitat for a wide array of marine species, as well as food for millions of people around the world — can recover from such catastrophes, in part because of a lack of long-term studies tracking damaged reefs. Now, a new study suggests that, given time and the right conditions, even once-decimated reefs can recoup their losses.

Did three convicts survive their escape from Alcatraz? Modern modeling adds to a decades-old mystery

Wed, 14 Jan 2015 10:11:00 -0500

The former Alcatraz Federal Penitentiary on Alcatraz Island in San Francisco Bay. Credit: Jon Sullivan, public domain

Twenty-first century science is shedding new light on a 53-year-old mystery involving one of the country’s most notorious prisons: Did three convicted bank robbers survive their escape attempt from Alcatraz Island? New results, presented at the American Geophysical Union’s (AGU) annual meeting in San Francisco last December, suggest there’s a chance they did.

Pliocene tropical oceans were warmer after all

Tue, 04 Nov 2014 10:08:07 -0500

Credit: ©Shutterstock.com/holbox.

Scientists may have overturned the idea that Earth’s tropical oceans were the same temperature during the Early to Middle Pliocene — between about 5 million and 3 million years ago — as they are today, despite the world being a far warmer place then.

Bare Earth Elements: Search the seafloor firsthand (and live!)

Thu, 25 Sep 2014 11:38:35 -0400

If you’ve ever wanted to take a dive into the ocean depths and explore the seafloor below the waves, but just haven’t had the time (or financing) to build your own deep-sea submersible, here’s another solution. NOAA’s 68-meter Okeanos Explorer — the only federally funded ship dedicated to “solely to exploration” — is currently trolling the Atlantic Ocean on the three-week third leg of a mission dubbed “Our Deepwater Backyard: Exploring Atlantic Canyons and Seamounts 2014," and it’s offering to take guests along for part of the ride.

XPRIZE offers new ocean health awards

Tue, 29 Oct 2013 18:45:35 -0400

The newest XPRIZE will be awarded for studying ocean acidification. Jerry Reid, U.S. Fish and Wildlife Service

XPRIZE, the organization that used competition to propel the development of private space travel and super-efficient vehicles, is now making a commitment to improving ocean health.

Tracking plastic in the oceans

Tue, 24 Jan 2012 07:34:25 -0500

Researchers found this net and other debris floating in the Great Pacific Garbage Patch. ©Scripps Institution of Oceanography

The garbage patches floating in the oceans are not solid, giant floating islands of trash. In fact, most of the plasticsx are tiny fragments called microplastics. ©Scripps Institution of Oceanography

Plastic can affect everything from tiny invertebrates to fish to large marine mammals. ©Scripps Institution of Oceanography

Despite worldwide efforts to curtail plastic use — to ban plastic grocery bags, to switch to reusable water bottles instead of disposable plastic bottles, and to get rid of the microplastics in cosmetics, for example — we still produce more than 260 million tons of plastic each year. Almost a third of that plastic goes into disposable, one-time-use items. Only about 1 percent of it is recycled globally, so much ends up in landfills. Worse still, some of the plastic winds up in the world’s oceans.

Blogging on EARTH: First dispatches from EGU

Thu, 05 Jan 2012 06:41:58 -0500

EARTH’s Carolyn Gramling is taking in the European Geophysical Union meeting this week in Vienna, Austria. Here are some of the sessions that have caught her interest so far.

How many thunderstorms are there around the world at any point in time?

About a century ago, scientists thought that number was about 2,000, based on an estimated number of lightning flashes per second (back then, thought to be about 100). Nowadays, of course, we have much better estimates of lightning flashes — satellite observations suggest there are actually only 45 flashes per second.

Natural dust may be harmful to ocean organisms

Thu, 05 Jan 2012 06:41:58 -0500

Although human-made aerosols sometimes are toxic, natural aerosols from deserts and volcanoes are important contributors to ocean fertilization. Now, new research suggests that natural aerosols have their downside too — and the impact of natural aerosols on ocean organisms could influence predictions of future climate change.

Of sounds and cetaceans: Quieting a noisy underwater world

Thu, 05 Jan 2012 06:41:58 -0500

Marine mammals live in a world of sound. In the open ocean, whales and dolphins depend on sound waves, using echolocation to navigate, find food, attract mates and communicate. But their clicks and calls are not the only noises underwater: Oil and gas exploration, seafloor mapping, and ship and submarine navigation have increased dramatically over the past few decades, making the world’s oceans noisier than ever.

Sea sprawl: Into the blue frontier of ocean development

Thu, 05 Jan 2012 06:41:58 -0500

Picture it: Dozens of kilometers off the coast of Texas, a giant polygon-shaped cage constructed of steel ribs and mesh netting floats 30 or so meters beneath the waves. The cage, moored to the seafloor, is filled with tens of thousands of teeming, silvery fish. Several kilometers away, offshore wind turbines sprout from the sea surface in a curving line, their spindly white arms churning the atmosphere. Still farther along the horizon, a massive oil platform squats heavily on four stumpy legs over its parcel of ocean, pipes plunging 11 kilometers into deep reservoirs within the seafloor. In the open waters between these industries, tankers and commercial fishermen follow snaking shipping lanes that lead them toward the coast.

Shell-shocked: How different creatures deal with an acidifying ocean

Thu, 05 Jan 2012 06:41:58 -0500

Ries and one of his students collect specimens. Justin B. Ries

An aragonite conch shell reared under current atmospheric carbon dioxide levels (400 ppm) appears normal, but... Justin B. Ries

...when reared under elevated (2,850 ppm) levels, it shows clear signs of dissolution, especially at the upper lip of the shell. Justin B. Ries

An aragonite quahog shell reared at current (400 ppm) atmospheric carbon dioxide levels shows well-formed ridges. Justin B. Ries

Under elevated (2,850 ppm) carbon dioxide, however, the ridges on the shell are nearly dissolved away. Justin B. Ries

A tropical pencil urchin (high-magnesium calcite shell) reared under current (400 ppm) atmospheric carbon dioxide conditions still has well-formed spines. Justin B. Ries

When reared at elevated (2,850 ppm) carbon dioxide, however, another urchin's spines are nearly dissolved away. Justin B. Ries

Justin Ries look at 18 species of marine calcifiers, including crustaceans, corals, bivalves, gastropods, coralline algae and urchins. Justin B. Ries

Staghorn corals, such as these off of Belize, are more vulnerable to ocean acidification because they build their shells from aragonite, not calcite. Castillo, UNC-Chapel Hill

To survive in the ocean, soft-bodied organisms must possess one of five traits: big teeth, toxic flesh, invisibility, quickness or a hard shell. Most marine organisms that employ the latter, called calcifiers, build their hard shells from the mineral calcium carbonate. However, increasing atmospheric carbon dioxide levels are making the oceans more acidic — which, in turn, is reducing the concentration of carbonate ions dissolved in seawater that organisms use to build their protective shells and skeletons. Calcifying marine organisms — such as clams, crabs, corals and conchs — may soon find themselves short on building material.

Voyage to the plastic vortex

Thu, 05 Jan 2012 06:41:58 -0500

SEAPLEX researchers examine a stuffed toy dog after it was collected along with ghost net debris on Aug. 15, 2009. 2009 Scripps Institution of Oceanography Photo credit: J. Leichter

Out in the middle of the northern Pacific Ocean, a giant floating mess of plastic debris is drifting and bobbing among the waves. Scientists call this expanse of litter, which stretches for hundreds of kilometers across open sea, the Great Pacific Garbage Patch. But before last summer, there was little information about how large the patch really is, what types of debris are out there and what kind of impact it is having on ocean life.