January 2019 on EARTH Magazine

Thirsty mantle: Subduction zones swallow more water than thought

Wed, 30 Jan 2019 15:26:27 -0500

A seismic study of part of the Pacific Plate diving beneath the Mariana Trench has revealed that old and cold subducting plates, like the Pacific, likely carry a lot more water into the mantle than previously realized. Credit: K. Cantner, AGI

For all the water stored in oceans, ice and other reservoirs at Earth’s surface, there’s likely even more in the planet’s interior, where it plays important roles in many geological processes, including the formation of magma and the lubrication of earthquake-producing fault zones. Uncovering just how much water is inside Earth — and the extent to which it moves back and forth between the surface and subsurface — has long been a challenge for scientists interested in understanding the planet’s water cycle. A new study peering beneath the Mariana Trench in the Western Pacific has revealed that some subduction zones might pull significantly more water into Earth’s interior than previously thought.

Deep drilling reveals how impact crater's hidden ring formed

Tue, 15 Jan 2019 14:20:08 -0500

When the 15-kilometer-wide Chicxulub meteorite slammed into what is now Mexico’s Yucatán Peninsula 66 million years ago, it was moving at more than 20 kilometers per second. The impact blasted a hole 200 kilometers wide and more than 30 kilometers deep in Earth’s surface. The forces involved in such impacts are colossal — many orders of magnitude greater than the largest human-made explosions — and scientists have traditionally relied on models to explain what happens in the moments after impact. But in a new study looking at shocked rocks retrieved from the depths of the buried Chicxulub Crater, scientists have determined how the crater’s “peak ring” formed in mere minutes.

Redefining Dinosaurs: Paleontologists are Shaking the Dinosaur Family Tree to its Roots

Fri, 11 Jan 2019 15:45:10 -0500

The current dinosaur family tree, which is fundamentally based on differences in hip morphology, has been in use since 1887. Scientists have recently proposed reorganizing some of the tree's biggest branches. Credit: K. Cantner, AGI.

What traits distinguish one dinosaur from another? For many, that question probably conjures characteristics like the massive jaws of tyrannosaurs, the distinctive horns and plates of ceratopsids and stegosaurs, and the exceedingly large bodies of sauropods and their kin. But for paleontologists looking to classify different dinosaurs, it’s all about the shapes, or morphologies, of the animals’ bones.

Where on Earth? - January 2019

Wed, 26 Dec 2018 13:35:19 -0500

Click to enlarge photo

Clues for January 2019:

This Eastern Sierra Nevada lake, the creek that feeds it and the basin it lies in, share a name that references a gang of outlaws who escaped from a Carson City, Nev., prison and hid out here in 1871.
The cliff towering above the lake displays complex folding and faulting of Lower Paleozoic metasedimentary rocks, including a faulted syncline (middle left in photo) that bears the same name as the cliff.
The rocks are part of the Mount Morrison Pendant, which consists of Cambrian to Permian sedimentary layers that were altered by intrusion of granitic plutons during the Mesozoic. The pendant takes its name from the largest mountain surrounding the lake (not pictured), which was named for a posse member killed in a shootout while apprehending the outlaw gang.

Melting glaciers shift Earth's axis

Fri, 21 Dec 2018 11:15:54 -0500

A perfectly round desk globe spins evenly on a fixed axis, but that’s not the case with Earth, which wobbles as the position of its spin axis — the imaginary line running between the North and South poles — slowly drifts over time. In a new study in Earth and Planetary Science Letters, scientists suggest that there are three main reasons for the movement of Earth’s spin axis, called polar motion.

Quirky lunar swirls expose the moon's secret past

Fri, 21 Dec 2018 11:09:44 -0500

The bright and dark shading characteristic of lunar swirls is seen in this oblique view looking east over the Reiner Gamma formation. The image was taken by the Lunar Reconnaissance Orbiter. Credit: NASA/Goddard Space Flight Center/Arizona State University.

Lunar observers have long noted mysterious “swirls,” patterns of alternating bright and dark shading, adorning the lunar surface. The popular Reiner Gamma formation — first described by Renaissance astronomers and now beloved by backyard astronomy enthusiasts — is one such lunar swirl.

Mesosaurs may have spent time on land

Fri, 21 Dec 2018 11:06:27 -0500

Mesosaurs were well adapted to life in the water, but adults may have also spent time on land. Credit: Roman Yevseyev and Graciela Piñeiro.

Mesosaurs are famous for being the earliest-known fully aquatic reptiles. With their whip-like tails, webbed feet and nostrils on top of their heads, the 2-meter-long reptiles appear to have been well adapted for life in the water. But in a new study, scientists have found fossil evidence that mesosaurs may have spent some of their adult lives on land.

Ocean circulation change suffocating Gulf of St. Lawrence

Fri, 21 Dec 2018 11:03:00 -0500

Research suggests that the Gulf Stream is shifting to the north, such that it's impinging on the flow of the Labrador Current near the Tail of the Grand Banks and reducing the supply of well-oxygenated water to the Gulf of St. Lawrence. Credit: K. Cantner, AGI.

Estuaries are among the most nutrient-rich and biologically productive areas of the ocean, and the Gulf of St. Lawrence, where freshwater from the Great Lakes and the St. Lawrence River meets the salty Atlantic Ocean in eastern Canada, is the largest estuary in the world. But the biodiversity and long-thriving fisheries of the Gulf of St. Lawrence could be threatened by declines in oxygen levels over the last half century. A new study suggests that a large-scale shift in Atlantic Ocean circulation is dumping warmer, oxygen-poor water into the gulf.

Earliest art found in South Africa

Fri, 21 Dec 2018 10:59:32 -0500

Blombos Cave, located along the South African coast about 300 kilometers east of Cape Town, has been excavated since 1991, revealing materials left by Homo sapiens between 100,000 and 70,000 years ago. A closer look at some curious red lines on a flake of rock found in the cave in 2011 has confirmed they were drawn by humans as early as 73,000 years ago, predating the earliest-known forms of art by as much as 30,000 years.

Rising carbon dioxide may raise risk of nutrient deficiencies in humans

Fri, 21 Dec 2018 10:54:40 -0500

In a new study, researchers found that levels of zinc, iron and protein in some grains and legumes will drop as atmospheric carbon dioxide concentrations rise. Credit: public domain.

Plants absorb carbon dioxide to fuel their growth. As humans increase the amount of the greenhouse gas in the atmosphere, more will be available to vegetation around the world. But according to a new study, too much carbon dioxide might eventually lead to plants that are deficient in key nutrients for humans, which could be especially detrimental in the developing world.

Early mammal reproduced like a reptile

Fri, 21 Dec 2018 10:51:50 -0500

A mother found fossilized alongside 38 of her young is offering a rare glimpse into early mammalian reproductive strategies. Unearthed in northeastern Arizona, the 184-million-year-old fossils are from specimens of Kayentatherium wellesi, an early mammal-like tritylodont that falls between reptiles and true mammals on the evolutionary tree.

Columbia River basalts erupted faster than thought

Fri, 21 Dec 2018 10:49:09 -0500

Lava flows of the Wanapum Basalt, the second-youngest formation of the Columbia River Basalt Group (CRBG), are exposed in Palouse Falls State Park along the Palouse River in eastern Washington. Researchers recently found that most of the CRBG lava erupted over a period of about 758,000 years, faster than previously thought. Credit: Jennifer Kasbohm, Princeton University.

Editor’s note: This story appeared in print in the January issue of the magazine. The version below has been updated to note that the areal extent of the Columbia River Basalt Group (CRBG) exceeds 200,000 square kilometers. This value was previously given as 163,700 square kilometers. Additionally, the story has been amended to acknowledge prior research that suggested that more than 90 percent of the CRBG volume erupted over a roughly 1.1-million-year period.

Arctic warming causes Siberian cooling

Fri, 21 Dec 2018 10:45:48 -0500

New research suggests that Siberia's anomalously cold winters in recent years may have been caused by melting sea ice in the Barents-Kara Sea. Credit: Dmitry A. Mottl.

The Arctic is warming faster than anywhere else on Earth, and fall sea-ice extents have been trending downward for decades. But while the region is heating up, that northerly warming seems to be having the opposite effect on some midlatitude locations: Parts of Siberia near the Ural Mountains, for example, have had anomalously cold winters in recent decades.

Ancient collision left a bit of Europe behind in Britain

Fri, 21 Dec 2018 10:37:02 -0500

The ancient landmasses of Laurentia, Avalonia and Armorica collided 400 million years ago, contributing pieces to the island that is today Great Britain. Credit: K. Cantner, AGI.

Great Britain is famously considered the birthplace of modern geology, and the many layers and terranes of rocks that make up England, Wales and Scotland have been studied and mapped for centuries. But that doesn’t mean scientists fully understand the island’s geologic past. In a new study, researchers looking at unusual volcanic rocks in southern England found previously unrecognized evidence of the island nation’s past connection to mainland Europe.

The geology of kidney stones revealed

Fri, 21 Dec 2018 10:31:39 -0500

Kidney stones are an excruciatingly painful problem for 10 percent of the world’s population. In a new study applying geobiological methods to the study of human kidney stones, researchers have shed light on how the stones form, and revealed that they partially and repeatedly dissolve inside the kidney — which could help in developing new protocols to treat the pervasive affliction.

Oman ophiolite suggests subduction started with a shove

Fri, 21 Dec 2018 10:28:47 -0500

Past research has suggested two mechanisms by which subduction zones may form along an area of lithospheric weakness: spontaneous sinking of denser crust and lithosphere, and forced convergence driven by lateral movement of a plate. A new study suggests that the latter was responsible for the formation of a fossil subduction zone off the Arabian Peninsula beginning about 104 million years ago. Credit: K. Cantner, AGI.

Plate tectonics is a fundamental control on how Earth operates and is important for the planet’s habitability, but how this crustal recycling process got started has long been a mystery. A new study examining some uniquely coupled metamorphic and volcanic rocks in Oman is adding some needed clarity about the initiation of subduction zones, a critical component in plate tectonics.

Benchmarks: January 12, 1888: "Schoolchildren's Blizzard" Strikes the Great Plains

Fri, 21 Dec 2018 10:25:02 -0500

The Jan. 12, 1888, "Schoolchildren's Blizzard" swept across the Great Plains, killing at least 235 people — and possibly up to 500, according to some estimates — many of whom were children on their way home from school. Illustrations showing "Scenes and Incidents from the Recent Terrible Blizzard in Dakota" were published in the Jan. 28, 1888, edition of Frank Leslie's weekly newspaper. Credit: public domain.

By mid-January 1888, the Great Plains had seen ice storms, frigid temperatures and above-average snowfall. On the morning of Jan. 12, however, the weather was unseasonably warm and sunny, with temperatures reaching well above freezing in places. Many people, including children on their way to school, left home without winter coats, hats or mittens. In a matter of hours, everything changed.

Down to Earth With: Clay mineralogist Warren Huff

Fri, 21 Dec 2018 10:11:59 -0500

Clay mineralogist Warren Huff taught at the University of Cincinnati (UC) for 55 years. He is still active as a professor emeritus and is a great supporter of bringing UC alumni together, especially at Geological Society of America annual meetings. Credit: courtesy of Warren Huff.

Two distinct images come to mind when I think of Warren Huff, my former doctoral adviser: one in which he is enthusiastically teaching and mentoring students both in and out of the classroom, and one in which he is sitting around a fire, playing guitar and leading a group of geologists in science-themed sing-alongs. Both images encapsulate the kind of person he is: a leading scholar in the field of clay mineralogy who lives life with gusto.

Geologic Column: Muinntir a' ghlinne so

Fri, 21 Dec 2018 10:06:22 -0500

"Pibroch" signifies a Scottish piper's variations on a musical theme. Credit: Alberto Garcia, CC BY-SA 2.0.

“The Gaelic word “pibroch” isn’t one you come across every day. It signifies a Scottish piper’s variations on a musical theme. Although the theme may often be warlike, many pibrochs are laments for the “tears of things,” the lacrimae rerum, or tragedy of existence, of which the old Romans wrote. In 1966, Dionne Warwick turned the popular song “Alfie” — which was composed for the movie of the same name and opened with the iconic line “What’s it all about, Alfie?” — into a poignant lament for human existence that always reminds me of a pibroch.

Comment: How to tell a good science story

Thu, 20 Dec 2018 11:44:54 -0500

The relative shapes of selected paradigms for science stories. Solid black lines show the relationship between the main character's fortune and the progression of a story from start to finish, relative to an average day (dotted line). Credit: figure shared with permission from Canadian Science Publishing under CC BY 4.0.

Everyone has a story to tell. Scientists are no exception, especially given that scientific studies can take researchers to far-flung places around the planet, lead to amazing new discoveries about the world we live in and produce challenges that provide the drama that is so important for a great story. Stories have the power to transport listeners to the places and experiences the storyteller is sharing with them. What better way is there to show that science is relevant, exciting and conducted by people who are passionate about what they do?

Our top tips for adding storytelling to your repertoire

Thu, 20 Dec 2018 11:40:22 -0500

(from Green et al., Facets, February 2018)

Identify your take-home message first. Start with the end in mind.

Remember the shape of your story. Tracking the main character’s fortune over time moves the story forward.

Consider the scale and timing of your story. Cut irrelevant background, processes and methods if they don’t move the story forward in a compelling way.

Eyes in the sea: Swarms of floating robots observe the oceans

Tue, 18 Dec 2018 12:31:05 -0500

When Scripps biological oceanographer Peter Franks needed a way to mimic planktonic movements in the ocean, Scripps research oceanographer Jules Jaffe created low-cost "miniature autonomous underwater explorers," or M-AUEs. The M-AUEs can be deployed in swarms to track planktonic movements as well as small-scale circulation patterns, oil spill dispersion or even sewage movement. Credit: Jaffe Lab for Underwater Imaging, Scripps Oceanography, UC San Diego.

In 1999, Peter Franks, a biological oceanographer at Scripps Institution of Oceanography in San Diego, published a hypothesis that, to his knowledge, nobody had previously considered. Using a mathematical model, he showed how tiny zooplankton and phytoplankton could interact with ocean currents driven by internal waves — slow-moving waves within the ocean that form between water layers of differing density — and form patchy bands running parallel to shorelines. These patches of plankton could benefit from being squeezed together by wave action, he thought, by being better able to feed, survive or even reproduce.

Travels in Geology: Lhasa, Tibet: Journey to the roof of the world

Tue, 18 Dec 2018 11:23:06 -0500

No visit to the windswept Tibetan Plateau would be complete without seeing Mount Everest, the world's highest peak. Credit: Lon Abbott and Terri Cook.

Few destinations are as alluring as the wild and windswept Tibetan Plateau. With an average elevation of 4,500 meters, it is Earth’s highest tableland and one of the most isolated regions on the planet. Tibet’s capital, Lhasa, one of the world’s highest cities, is simply breathtaking — both literally, given the low oxygen levels at this altitude, and figuratively, with its mountainous backdrop and the gleaming whitewashed walls of Potala Palace, an enduring symbol of Tibetan Buddhism, rising high above the Old Town. As we saw firsthand when our family visited last summer, Lhasa — with its intricately painted statues, gilded-dome stupas housing Buddhist relics, and thousands of prayer wheels glistening in the flickering light of yak-butter candles — is a place that’s both above and apart from the rest of the world.

Getting there and getting around Tibet

Tue, 18 Dec 2018 11:21:22 -0500

“Tibet is a long way from most everywhere. There are no direct flights from North America, so it’s usually cheapest and most convenient to fly into a major Chinese city such as Beijing and then catch the next flight to Lhasa Gonggar Airport (LXA). Air China, Tibet Airlines, Sichuan Airlines and China Southern are among the carriers offering direct and connecting flights to Lhasa from most major Chinese cities. Sichuan Airlines and Air China also provide nonstop service from Kathmandu, Nepal. The Lhasa airport is located 65 kilometers south of the city center and takes about an hour to reach.

Geomedia: Film: 'First Man' navigates Neil Armstrong's journey between two worlds

Thu, 11 Oct 2018 20:41:32 -0400

Warning: Spoilers ahead

“First Man” is a vivid depiction of Neil Armstrong’s life during NASA’s ambitious and terrifying program to reach the moon. The film uses exquisite cinematography to portray the crowning achievement of the space race — Armstrong becoming the first human to walk on the moon on July 20, 1969. Directed by Damien Chazelle, who won an Academy Award for his direction of “La La Land,” the film navigates a fine line among the triumphs and tragedies of the Gemini and Apollo missions, while also telling the story of the home lives of the astronauts and their families. The dynamics in this human drama cannot be solely explained by physics.