How can you hide a large volcano here on Earth? Place it several miles below the surface of the Pacific Ocean.

Researchers, reporting this week in Nature Geoscience, have discovered just that: a hidden volcano so big it can rival some of the largest in the Solar System. (Think Olympic Mons on Mars.) For several million years, Tamu Massif, has been under cover in the northwest Pacific Ocean, about 1,000 miles east of Japan where three tectonic plates meet: the Pacific, the Farallon and the Izanagi.

Scientists knew there were underwater volcanoes in the Shatsky Rise but it was unclear whether Tamu Massif was a single volcano, or a composite of many eruption points. By integrating several sources of evidence, including core samples and data collected on board the JOIDES Resolution research ship, the authors have confirmed that the mass of basalt that constitutes Tamu Massif did indeed erupt from a single source near the center.

Tamu Massif stands out among underwater volcanoes not just for its size, but also its shape. It is low and broad, meaning that the erupted lava flows must have traveled long distances compared to most other volcanoes on Earth.

Although it rivals Olympic Mons in width and sheer area (about 120,000 square miles), it only rises about 13,000 feet above the sea floor. (Mons is about 14 miles tall! You can thank low martian gravity for that.) Tamu Massif’s tallest point rests at about 6,500 feet below the ocean surface.

“It’s not high, but very wide, so the flank slopes are very gradual,” says lead author William Sager, of the University of Houston. “In fact, if you were standing on its flank, you would have trouble telling which way is downhill. We know that it is a single immense volcano constructed from massive lava flows that emanated from the center of the volcano to form a broad, shield-like shape.”

Thankfully, the massive Tamu Massif is an inactive volcano. Sager and his team put the megavolcano at about 145 million years old, and believe it became inactive within a few million years after it was formed.

“Its shape is different from any other sub-marine volcano found on Earth, and it’s very possible it can give us some clues about how massive volcanoes can form,” Sager says. “An immense amount of magma came from the center, and this magma had to have come from the Earth’s mantle. So this is important information for geologists trying to understand how the Earth’s interior works.”

Image: Will Sager

While the planet warmed steadily at a rate of 0.13° C per decade since 1950, since 1998 it’s been on a hiatus, despite the fact that levels of carbon dioxide, the main greenhouse gas produced by human activities, continued a steady rise, reaching 400 parts per million for the first time in human history in May 2013.

Two researchers from Scripps Institution of Oceanography at UC San Diego discovered the reason for this hiatus, publishing their findings last week in Nature.

The reason for the warming break? Cooling in the eastern tropical Pacific Ocean. The team predicts that long-term global warming will resume when the tropical Pacific switches back to a warm state.

The researchers arrived at their conclusion using innovative computer modeling methods to simulate regional patterns of climate anomalies. This enabled them to see global warming in greater spatial detail, revealing where it has been most intense and where there has been no warming or even cooling.

The current cooling phase began just after a strong El Niño year in 1998. The study considers the tropical Pacific Decadal Oscillation (PDO), a climate cycle that plays out over the course of several decades. Within this large pattern fall El Niño and La Niña, well-known faster cycles that cause shifts in the distribution of warm water in the equatorial Pacific Ocean. While El Niño and La Niña last only a few years, the PDO lasts several decades. The last time it was in a cooling phase—cooling waters in the eastern equatorial Pacific Ocean—it lasted from roughly 1940 to the early 1970s. The researchers are unsure how this long this phase will last.

“That speaks to the challenge in predicting climate for the next few years,” says study co-author Shang-Ping Xie.  “We don’t know precisely when we’re going to come out of [the hiatus] but we know that over the timescale of several decades, climate will continue to warm as we pump more greenhouse gases into the atmosphere.”

“These compelling new results provide a powerful illustration of how the remote eastern tropical Pacific guides the behavior of the global ocean-atmosphere system, in this case exhibiting a discernible influence on the recent hiatus in global warming,” says Dan Barrie, program manager at the NOAA Climate Program Office.

Image: Kosaka, Xie/Scripps

Happy Earth Day! We would like to share a few recent headlines for you to peruse to ponder and protect our planet…

Pollution
From high to low, all around the world, pollution affects our world. Recent headlines show that “Toxic chemicals are accumulating in the ecosystems of the Himalayas and the Tibetan plateau,” according to Nature. Tiny plastic particles aren’t just trouble in the oceans; the Great Lakes contain millions of microplastics, too. The New York Times’ Dot Earth blog has a short post about the importance of not littering. And National Geographic has an article about how pollution on land can affect marine life like dolphins and local sea otters.

Colorado River
While many U.S. rivers have problems with pollution, the Colorado River’s mismanagement, overuse and drought put it atop the list of Endangered Rivers of 2013. National Geographic has an entire series on the Colorado River delta, and the New York Times has offered both an article and video last week on the region’s hopeful revival.

Drought
Speaking of drought… Do drought-stressed trees cry for help? French scientists are listening for clues. Climate change was not responsible for last summer’s Midwestern drought, according to NOAA, but then what was? And how might we be able to predict future droughts?

Climate Change
Climate change may not have caused of the recent drought, but it is responsible for other devastating events and looming disasters: bumpier flights, more storms, bark beetle plagues, drowned islands, failures in agriculture systems and more extinctions. Researchers are also getting a better handle on tracking climate change through mapping ocean eddies and looking at historic ocean temperatures and air pressure.

Ecology
How do species react to environmental changes? Rapid evolution, according to one study. Another study suggests that endangered species are already doomed. And Nature offers an update on a decades-long study of habitat fragmentation in the Amazon.

Energy
How has energy usage in our country changed over the past two hundred years? NPR has a graph (or four) for that. In response, Scientific American presents a diagram illustrating our potential for future alternative energy use and resources accompanying an article titled, “How to Power the World without Fossil Fuels.” Germany seems to have taken notice—the European country has ambitious renewable plans. But it’s not the only one. The U.S. had a huge year in 2012 for wind power. And, heading across the country soon? How about a solar-powered flight?

Earth Day
Finally, let’s truly celebrate the planet’s holiday with history, maps, jokes about Earth Day, and facts and photos of our beautiful home.

Image: Terra/ASTER/NASA and NASA Earth Observatory

Now, new evidence, published last week in Nature, supports the theory that comets delivered a significant portion of Earth’s oceans, which scientists believe formed about 8 million years after the planet itself.

“Life would not exist on Earth without liquid water, and so the questions of how and when the oceans got here is a fundamental one,” says University of Michigan astronomer Ted Bergin. “It’s a big puzzle and these new findings are an important piece.”

Bergin is a co-investigator on HiFi, the Heterodyne Instrument for the Infrared on the Hershel Space Observatory. With measurements from HiFi, the researchers found that the ice on a comet called Hartley 2 has the same chemical composition as our oceans. Both have similar D/H ratios. The D/H ratio is the proportion of deuterium, or heavy hydrogen, in the water. A deuterium atom is a hydrogen with an extra neutron in its nucleus.

This was the first time ocean-like water was detected in a comet. “We were all surprised,” admits Bergin.

Six other comets HiFi measured in recent years had a much different D/H ratio than our oceans, meaning similar comets could not have been responsible for more than 10 percent of Earth’s water.

The astronomers hypothesize that Hartley 2 was born in a different part of the solar system than the other six. Hartley most likely formed in the Kuiper belt, which starts near Pluto at about 30 times farther from the sun than Earth is. The other six hail from the Oort Cloud more than 5,000 times farther out.

“The results show that the amount of material out there that could have contributed to Earth’s oceans is perhaps larger than we thought,” speculates Bergin.

Image courtesy of NASA

A new analysis of data from NASA’s Galileo spacecraft reveals that beneath the surface of Jupiter’s volcanic moon Io is an “ocean” of molten or partially molten magma. The magma ocean layer appears to be more than 30 miles thick, making up at least 10 percent of the moon’s mantle by volume. The blistering temperature of the magma ocean probably exceeds 2,200 degrees Fahrenheit (1,200 degrees Celsius). Hotcha!

NASA’s Voyager spacecraft discovered Io’s volcanoes in 1979 and they are the only known active magma volcanoes in the solar system other than those on Earth. The energy for the volcanic activity comes from the squeezing and stretching of the moon by Jupiter’s gravity as Io orbits the immense planet, the largest in the solar system.

Even though the magnetic-field data was taken from Galileo fly-bys of Io in October 1999 and February 2000, it took awhile to detect this magma layer. ScienceInsider reports that

high-flying volcanic debris frustrated space physicists’ attempts to use Jupiter’s powerful magnetic field as a probe of Io’s interior.

The current analysis, over ten years in the making, was published in this week’s edition of Science.

From a hot ocean to hot Jupiters…  Hot Jupiters describe large gaseous exoplanets that orbit very close to their parent star. Some of these hot Jupiters are just plain crazy weird, say scientists, because they orbit their star in the opposite direction.

“That’s really weird, and it’s even weirder because the planet is so close to the star,” said Frederic A. Rasio, a theoretical astrophysicist at Northwestern University. “How can one be spinning one way and the other orbiting exactly the other way? It’s crazy. It so obviously violates our most basic picture of planet and star formation.”

When scientists find something weird and crazy, they investigate. And that’s just what Rasio and his colleagues did. Using large-scale computer simulations, they are the first to model how a hot Jupiter’s orbit can flip and go in the direction opposite to the star’s spin. Gravitational perturbations by a much more distant planet result in the hot Jupiter having both a “wrong way” and a very close orbit, according to their research, published this week in Nature.

In other exoplanet news… The Kepler mission’s primary goal is to find Earth-like planets orbiting Sun-like stars, and now you can help find them, too! UC Berkeley astronomers aimed a radio telescope in the direction of Kepler’s most Earth-like candidates last weekend. Once they acquire data on a total of 86 Earth-like planets, they’ll initiate a coarse analysis and then, in about two months, ask an estimated 1 million SETI@home users to conduct a more detailed analysis on their home computers. Join SETI@home or learn more information about the project here.

Io image: NASA/JPL/University of Michigan/UCLA

Villy Christensen of the University of British Columbia (UBC) said, “Yes, there will be fish left, but it will be a very different ocean from the ones your parents and grandparents knew and even different from now.”

The biggest difference? Large, predatory fish will be gone.

In fact, over the last one hundred years, the population of these large, top-of-the-food-web fish has declined by two-thirds, half of that decline occurring only in the last 40 years. And that population continues to decline.

There will be many small fish left, but not necessarily the ones we eat.

He and his colleague, Reg Watson, also from UBC, are working with scientists, governments and NGOs to build a global database of fishing efforts to truly understand what’s going on in the world’s oceans.

Seventy-six million tons of fish are consumed each year, and Watson found that we are fishing harder for the same or less result. It’s possible that we’ve hit “peak fish,” according to Watson. Jacqueline Alder of the UN Environment Program in Kenya is working with the UBC group, looking at their models in terms of marine biodiversity and sustainability. She urged that we must reduce fishing efforts immediately to allow fish stocks to rebuild.

In addition, there was much discussion around the non-sustainability of using fish for feedstock in aquaculture and agriculture– fish we are not directly eating. The science and technology have to get better to use plant-based feedstock for fish farms.

Christensen stressed this is a large view of what’s going on in the entire ocean ecosystem, not just one area or species.

For more focused, local information, read our recent article on banning shark finning, and the San Francisco Chronicle had a devastating article last week stating that some of the fish in the Delta may be too far gone to save from extinction.

Image: Mila Zinkova/Wikimedia