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mary caperton morton

Sierra Nevada snowpack lowest in 500 years

With several ski resorts closing early last winter in California’s Sierra Nevada Mountains due to lack of snow, many people suspected the snowpack for the year was on the low side. This suspicion has been confirmed: Snow levels for the winter of 2014–2015 registered as the lowest in the last 500 years.
 
07 Jan 2016

Treated water that's too pure lets arsenic sneak in

With California’s water resources dwindling to alarmingly low levels, the Orange County Water District (OCWD) has pioneered a high-tech approach for recycling wastewater into potable tap water instead of discharging it into the ocean. The purification process is so thorough, however, that it might actually make the water too clean: In a new study, researchers have found that the ultra-purified water is vulnerable to contamination by naturally occurring arsenic in underground storage aquifers.
 
03 Jan 2016

South African cave system reveals new early human ancestor

The Rising Star Cave system, near Johannesburg, South Africa, has never been extensively explored because of its complexity and extremely narrow passages. But in 2013, when a team of intrepid cavers from the Speleological Exploration Club of South Africa pushed through a narrow 12-meter-long chute with an average width of only 20 centimeters, they discovered a chamber filled with what looked like human bones.
 
31 Dec 2015

Unshelled ancestor fills big gap in turtle family tree

Turtles may seem like innocent creatures, but the uniquely shelled reptiles have long posed a problem for paleontologists. Shelled turtles are plentiful in the fossil record, but specimens of their intermediate forebears — the missing links between ancestral unshelled reptiles and modern turtles — have remained elusive. Now, a closer look at the skull of what may be one of the earliest turtle relatives is filling gaps in the turtle family tree.
 
28 Dec 2015

Oldest marine turtle found in Colombia

A 120-million-year-old sea turtle recently discovered in Colombia is about 25 million years older than the previously oldest-known marine turtle. Despite its age, the new 2-meter-long specimen is very similar to living marine turtles and was placed in the group Chelonioidea, which includes the modern Hawksbill turtle and green sea turtle.
 
28 Dec 2015

Midwest's hybrid rift formed in three stages

Middle America is not often recognized for its interesting geology, yet it boasts one of the largest and most unusual geologic features in the country: the Midcontinent Rift, which stretches 3,200 kilometers in two arms from Lake Superior to Oklahoma and Alabama. Subsurface imaging of the rift has revealed that it’s not just a rift, it’s also what’s known as a large igneous province, making it a hybrid geologic feature not seen anywhere else in the world. A new modeling study is offering a more complete story of how the Midcontinent Rift evolved, in three stages. 
 
23 Dec 2015

Ancient African villages shed light on Earth's magnetic field

Throughout Earth’s history, the planet’s magnetic field has changed polarity hundreds of times, with the magnetic north and south poles swapping positions. These reversals sometimes occur every few thousand years, or after hundreds of thousands of years. The last known magnetic reversal took place nearly 800,000 years ago, leaving many to wonder if we’re overdue for a reversal. Now, research from southern Africa, an understudied region, analyzing magnetized minerals preserved in the charred floors of 1,000-year-old torched huts has shed light on geomagnetic patterns that may indicate — or perhaps even trigger — such a switch. 
 
15 Dec 2015

Balanced boulders in earthquake country highlight interconnected faults

Precariously balanced boulders look like bizarre accidents in any landscape, but when they’re found in regions famous for frequent earthquakes, such gravity-defying formations are even more improbable. Scientists have long wondered about an odd collection of dozens of balanced boulders in the San Bernardino Mountains that seemingly should have been toppled centuries ago by the earthquakes that regularly shake Southern California. Even stranger, these car- to house-sized granite boulders are located within 10 kilometers of the active San Andreas and San Jacinto faults. Now, new detective work on 36 of the boulders is giving scientists clues about the connections between these faults. 
 
14 Dec 2015

Chinese cave art reveals record of climate change

In times of drought, Dayu Cave in the Qinling Mountains of central China has remained a reliable source of water, and since at least the 16th century, thirsty visitors to the cave recorded their pilgrimages on the walls. Now the graffiti — rendered in black pigment on the yellow cave walls — is providing scientists with a unique record of how climate change affected nearby communities between 1520 and 1920. 
 
13 Dec 2015

The Snowmastodon Project: Mammoths and mastodons lived the high life in Colorado

In fall 2011, a bulldozer driver in Snowmass, Colo., unearthed an unprecedented trove of Pleistocene-aged fossils. Over the next few months, “Snowmastodon” became one of the largest fossil excavations ever. Scientists have already learned a lot from the bones.

13 Dec 2015

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