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Once a year, Piermont Pier becomes a field station, and local students, a team of environmental investigators. On Tuesday, scientists at Lamont-Doherty Earth Observatory led students through a series of field experiments designed to teach them more about the Hudson River. The students took water chemistry measurements and compared them to the Hudson’s tidal cycles. They cored sediments from the river bottom and pictured their stretch of the Hudson covered in glaciers. They mapped out how high the river may rise under several CO2-emissions scenarios.

Max Cunningham, a graduate student at Lamont-Doherty, traveled to Costa Rica’s Mount Chirripó this past summer to test the idea that mountain glaciers carved the summit we see today. He and his colleagues hope to eventually pin down when Chirripó’s high-elevation valleys eroded into their current form. Check out a recap of their 2014 field season.

In a long running tradition known as Open House, Lamont-Doherty Earth Observatory opens its doors to the public. In talks and demonstrations, scientists share what they have been up to over the last year. Here is where to learn what makes some volcanoes more explosive than others; how deep ocean currents circulate the globe; what tree rings can tell us about climate change today and in times past. Researchers also share some of their tools for exploration, from unmanned robot submarines to portable seismometers to mass spectrometers that measure tiny bits of matter.

A new study by researchers at Lamont-Doherty Earth Observatory and Stony Brook University shows how ‘brown tide’ algae thrive in waters that are murky and low in inorganic nutrients.

Kenneth Hunkins, an oceanographer who made many key 20^th-century observations about the Arctic Ocean, often while camping for months on its frozen surface, died in his sleep at his home in Tappan, N.Y., on Sept. 2. He was 86. Columbia University’s Lamont-Doherty Earth Observatory, where he had spent his entire career, confirmed his death.

Death Valley is a land of extremes—among the hottest, driest and lowest points on earth. Why would anyone choose to spend spring break there?

“It just sounds very exotic,” says Nicholas Christie-Blick, a geology professor and research scientist at Columbia University’s Lamont-Doherty Earth Observatory. “It’s very far away from their personal experience.”

For decades, climate scientists have tried to explain why ice-age cycles became longer and more intense about 900,000 years ago, switching from 41,000-year cycles to 100,000-year cycles.  In a new study in the leading journal Science, researchers found that the deep ocean currents that move heat around the globe stalled or even stopped, possibly due to expanding ice cover in the north. The slowing currents increased carbon dioxide storage in the ocean, leaving less in the atmosphere, which kept temperatures cold and kicked the climate system into a new phase of colder but less frequent ice ages, they hypothesize.

Tiny one-celled organisms called radiolaria are ubiquitous in the oceans, but various species prefer distinct habitats. Thus it aroused considerable intrigue in 2012 when protozoa specialist O. Roger Anderson and colleagues published a study showing that radiolaria normally found near the equator were suddenly floating around in arctic waters above Norway. Was this a sign that global climate change was bringing an invasion of warm-weather plankton?

On a high ridge in Arizona’s Petrified Forest National Park, paleontologist Paul Olsen sits on the fallen trunk of a 215-million-year-old tree, now turned to stone. The tree once loomed 70 or 80 feet above a riverine landscape teeming with fish, turtles, giant crocodilians and tiny, early species of dinosaurs. From here, Olsen can survey the remnants of this lost world: miles and miles of surreal badlands, where sediments built up over millions of years have eroded back down to expose endless cross sections of brightly colored rocks. The layers represent tectonic movements, natural climate cycles, the growth and disappearance of lakes, buildups of river deltas. The petrified trees scattered across the landscape are only the most obvious fossils; others are bleeding out by the ton. It is perhaps the world’s richest trove of rocks from the late Triassic, when dinosaurs, and early mammals, got their evolutionary start. The Triassic was also a hothouse world: a time of high atmospheric carbon dioxide, rapid climate shifts, and fast-moving extinctions. Olsen thinks there may be much to learn from it for our own time.

As dates in geologic history go, the formation of the slender land bridge that joins South America and North America is a red-letter one. More than once over the past 100 million years, the two great landmasses have been separated by deep ocean waters. The narrow section of Central America that now unites them–at its narrowest along the isthmus of Panama–changed not just the world map, but the circulation of oceans, the course of biologic evolution, and probably global climate. The tortured product of diverse forces, today’s version of the isthmus was probably fashioned by volcanism and movements of tectonic plates somewhere between 15 million and 3 million years ago.

Gerardo Iturrino, a longtime engineer and ocean explorer at Lamont-Doherty Earth Observatory, passed away unexpectedly on March 12. A resident of nearby Nyack, he was 51; the cause was heart attack, said his family.

Researchers studying the rings of ancient trees in mountainous central Mongolia think they may have gotten at the mystery of how small bands of nomadic Mongol horsemen united to conquer much of the world within a span of decades, 800 years ago. The rise of the great leader Genghis Khan and the start of the largest contiguous empire in human history was propelled by a temporary run of nice weather.

On Feb. 20, Science published new research about the Pine Island Glacier on the West Antarctic Ice Sheet that suggests the glacier’s recent and rapid thinning and melting may continue for decades or centuries to come. The British Antarctic Survey’s Joanne Johnson’s research, done in collaboration with scientists at Lamont-Doherty, might not have been possible without Lamont’s effort to promote women scientists, honoring another woman scientist who helped map the ocean floor.

Terry Plank got hooked on volcanoes when her professor at Dartmouth took the students to Costa Rica and let them have lunch on Arenal, a famous volcano that was in the process of erupting. “They gave us each a pineapple and a can of tunafish and we had to figure out how to eat this stuff with our Swiss Army knives while sitting on a lava flow…It just looked like black rock, but every once in awhile a boulder at the end would fall off and you’d see it was completely red inside. And it made all these cool sounds and you’d feel these little earthquakes… It was totally cool. How could you not like that?”

Since 1949, scientists at Lamont-Doherty Earth Observatory have trekked to the far corners of the globe. Over oceans, continents and at both poles, Lamont-Doherty scientists have mapped large swaths of the planet to gain insight into its history and evolution. In honor of their accomplishments, many natural features bear their names, from faults on the seafloor to frozen islands off Antarctica.  Explore the map!

The jury is still out on how tropical storms will change as climate warms, but rising sea levels will almost certainly place more coastal property at risk of flooding, says a team of scientists writing in the journal Nature.

Two longtime oceanographers at Lamont-Doherty Earth Observatory, Arnold Gordon and Walter Pitman, have been elected fellows of the American Association for the Advancement of Science (AAAS), and will be formally recognized at the association’s annual meeting in Chicago in February.

Tourists flock to Italy to see Michelangelo’s David and other iconic hunks of Renaissance stone, but in a trip over spring break, a group of Columbia students got to visit rocks that have shaped the world in even more profound ways. In the limestone outcrops of Italy’s Apennine Mountains, geologist Walter Alvarez collected some of the earliest evidence that a massive fireball falling from space some 66 million years ago was responsible for killing off the dinosaurs. Geologists have trekked to the region since then to study that catastrophic event as well as others imprinted in these rocks.

Most earthquakes erupt suddenly from faults near Earth’s surface, and the big ones can topple cities. But miles below, rocks heated to the consistency of wax moving over thousands to millions of years may be the driving force behind some of these events.

The small town of Barrow, Alaska is perched on a point of land 320 miles above the Arctic Circle, where stark, flat tundra stretches in one direction and a vast expanse of Arctic Ocean extends to the horizon in the other. For most of the year a thick layer of sea ice covers this entire ocean. Even during the height of summer, a partial covering of ice remains, and the ocean temperature doesn’t rise above 35 degrees Fahrenheit. Despite these seemingly inhospitable conditions, tiny marine organisms thrive in this frigid environment.

Naturally occurring arsenic pollutes wells across the world, especially in south and southeast Asia, where an estimated 100 million people are exposed to levels that can cause heart, liver and kidney problems, diabetes and cancer. Now, scientists working in Vietnam have shown that massive pumping of groundwater from a clean aquifer is slowly but surely drawing the poison into the water. The study, done near the capital city of Hanoi, confirms suspicions that booming water usage there and elsewhere could eventually threaten millions more people. The study appears in the current issue of the leading journal Nature

In the northern hemisphere, ice sheets ebb and flow in 100,000-year cycles, driven by varying amounts of sunlight falling on Earth’s surface as its orbit and orientation toward the sun changes. But astronomical variations alone cannot explain why ice ages develop gradually but end quickly, in a few thousand years. Though the last ice age saw several peak-periods of sunlight, it was the last one—about 10,000 years ago—that caused the ice to withdraw from much of Europe and North America.

If some volcanoes operate on geologic timescales, Costa Rica’s Irazú had something of a short fuse. In a new study in the journal Nature, scientists suggest that the 1960s eruption of Costa Rica’s largest stratovolcano was triggered by magma rising from the mantle over a few short months, rather than thousands of years or more, as many scientists have thought. The study is the latest to suggest that deep, hot magma can set off an eruption fairly quickly, potentially providing an extra tool for detecting an oncoming volcanic disaster.

The risk of catching some nasty germ in the Hudson River just started looking nastier.  Disease-causing microbes have long been found swimming there, but now researchers have documented antibiotic-resistant strains in specific spots, from the Tappan Zee Bridge to lower Manhattan. The microbes identified are resistant to ampicillin and tetracycline, drugs commonly used to treat ear infections, pneumonia, salmonella and other ailments. The study is published in the current issue of the Journal of Water and Health.

The desert sultanate of Oman is home to some of the weirdest—and possibly most useful—rocks on earth. The stark Hajar mountains, near the border with Saudi Arabia, contain a chunk of earth’s mantle—a zone that makes up most of earth’s mass, but normally lies inaccessible to humans, far below the surface. Here, though, a sliver of mantle has made its way up to where we can see and touch it. The outcrop has drawn scientists looking for clues to the dynamics of the deep earth; the origins of life; and, most recently, ways to fight climate change.

Nearly 25 years after an international ban was placed on ivory, African elephants are being slaughtered at a rate that could bring about their extinction this century. By allowing the trade of ivory acquired before 1989 to continue, the ban put the burden on law enforcement to distinguish between legal ivory and poached. Now, a new method for dating elephant tusks, described in the latest issue of the Proceedings of the National Academy of Sciences (PNAS), could make it easier to enforce the ivory ban and save the African elephant from extermination say researchers. The method might also be applied to endangered rhinoceroses and other wildlife.

Twice humans have witnessed the wasting of snow and ice from Peru’s tallest volcano, Nevado Coropuna—In the waning of the last ice age, some 12,000 years ago, and today, as industrial carbon dioxide in the air raises temperatures again. As in the past, Coropuna’s retreating glaciers figure prominently in the lives of people below.

Eight hundred years ago, relatively small armies of mounted warriors suddenly exploded outward from the cold, arid high-elevation grasslands of Mongolia, and conquered the largest contiguous empire in history. Led by Genghis Khan and his sons and grandsons, the Mongols briefly ruled most of modern-day Russia, China, Korea, southeast Asia, Persia, India, the Middle East and eastern Europe. They reshaped world geography, culture and history in ways that still resound today. How did they do it? Among the forces at work: the Mongols’ fast horses and brilliant cavalry tactics; their openness to new technologies; and the political genius of Genghis himself. Now, a research group is looking into a possible other factor: climate change. The idea may have implications not only for our understanding of history, but for modern Mongolia and the wider world.

Mark Cane, an expert on the El Niño climate pattern, and Terry Plank, an authority on explosive volcanoes—both scientists at Columbia University’s Lamont-Doherty Earth Observatory--have been elected to the National Academy of Sciences. Membership in the National Academy, given for excellence in original scientific work, is one of the highest honors awarded to engineers and scientists in the United States.

A new study in the journal Geology is the latest to tie a string of unusual earthquakes, in this case, in central Oklahoma, to the injection of wastewater deep underground. Researchers now say that the magnitude 5.7 earthquake near Prague, Okla., on Nov. 6, 2011, may also be the largest ever linked to wastewater injection. Felt as far away as Milwaukee, more than 800 miles away, the quake—the biggest ever recorded in Oklahoma--destroyed 14 homes, buckled a federal highway and left two people injured. Small earthquakes continue to be recorded in the area.

A delay in the summer monsoon rains that fall over the southwestern United States and northwestern Mexico is expected in the coming decades according to a new study in the Journal of Geophysical Research.  The North American monsoon delivers as much as 70 percent of the region’s annual rainfall, watering crops and rangelands for an estimated 20 million people.

A nuclear test explosion set off last night by North Korea was far larger—perhaps by three or four times—than the country’s last known blast, say seismologists who have examined seismic waves coming from the site. The estimate suggests that the North Koreans are making steady progress toward building more forceful weapons.

Louise Rosen, a senior manager in Columbia University’s Office of Development and Alumni Relations, has been named director of a new office at Lamont-Doherty Earth Observatory that will oversee fundraising, communications, education and strategic initiatives. She will start the new position on Feb. 11.

As earth’s climate warms, scientists have tried to understand why the poles are heating up two to three times faster than the rest of the planet. Airborne dust, it turns out, may play a key role.

Scientists from Columbia University’s Earth Institute will present important new studies at the Dec. 3-7 meeting of the American Geophysical Union, the world’s largest gathering of earth and space scientists. Below: a chronological guide. Most researchers are at our Lamont-Doherty Earth Observatory (LDEO).More info: http://fallmeeting.agu.org/2012/ Reporters may contact scientists directly at any time, or call press officers:

Mercury, the planet closest to the Sun, may hold at least 100 billion tons of ice in permanently shaded craters near its north pole, NASA scientists announced Thursday. Radar images had led scientists to suspect for decades that Mercury had water, but NASA’s MESSENGER spacecraft, which began orbiting the planet in March 2011, is the first to confirm it.

During Hurricane Sandy the seas rose a record 14-feet in lower Manhattan. Water flooded city streets, subways, tunnels and even sewage treatment plants. It is unclear how much sewage may have been released as plants lost power or were forced to divert untreated wastewater into the Hudson River.

For much of the last decade, Klaus Jacob warned of New York’s vulnerability to severe flooding in a major storm. Rising seas and more extreme weather from a warming climate could cripple the New York region, he told anyone willing to listen. 

This spring, a Swedish scientist sparked international concern with a journal article saying that radioactive particles detected in 2010 showed North Korea had set off at least two small nuclear blasts--possibly in experiments designed to boost the yields of much larger bombs. Shortly after, the pot was stirred with separate claims that some intelligence agencies suspected the detonations were done in cooperation with Iran. Now, a new paper says the tests likely never took place—or that if they did, they were too tiny to have any military significance. The new report, by seismologists at Columbia University’s Lamont-Doherty Earth Observatory, will be published later this month in the journal Science & Global Security, where the earlier paper also appeared.

Summers on the Norwegian archipelago of Svalbard are now warmer than at any other time in the last 1,800 years, including during medieval times when parts of the northern hemisphere were as hot as, or hotter, than today, according to a new study in the journal Geology.

Water is on the minds of Rockland residents this summer, and not just because of the record U.S. drought. Rockland County’s main water provider, United Water NY, wants to build a treatment plant on the Hudson River that would deliver more freshwater to Rockland taps. Some people are in favor of boosting supply to this growing suburban region, a short drive from the George Washington and Tappan Zee bridges. Others are opposed, citing the cost, in energy and dollars, plus the danger to fish and other wildlife. As the project awaits approval from the state Department of Environmental Conservation, a new debate on water consumption has emerged. Should people be encouraged, or even required, to use less? And if so, how?

Over the past 450 million years, life on earth has undergone at least five great extinctions, when biological activity nosedived and dominant groups of creatures disappeared. The final one (so far) was 65 million years ago, when it appears that a giant meteorite brought fires, shock waves and tsunamis, then drastically altered the climate. That killed off the dinosaurs, setting the stage for mammals–and eventually us–to evolve. 

For the first time, scientists have identified tropical and subtropical species of marine protozoa living in the Arctic Ocean. Apparently, they traveled thousands of miles on Atlantic currents and ended up above Norway with an unusual—but naturally cyclic—pulse of warm water, not as a direct result of overall warming climate, say the researchers. On the other hand: arctic waters are warming rapidly, and such pulses are predicted to grow as global climate change causes shifts in long-distance currents. Thus, colleagues wonder if the exotic creatures offers a preview of climate-induced changes already overtaking the oceans and land, causing redistributions of species and shifts in ecology. The study, by a team from the United States, Norway and Russia, was just published in the British Journal of Micropalaeontology.

Daehyun Kim, a climate scientist at Lamont-Doherty Earth Observatory, has been recognized for early-career achievement in the atmospheric sciences by the American Geophysical Union, the world’s largest earth-sciences organization. Kim, 32, came to Lamont as a postdoctoral researcher in 2010, where he has focused on investigating the Madden-Julian Oscillation, a little-understood weather pattern that typically forms in the Indian Ocean and brings heavy rains and hurricanes to many parts of the globe.

Dendrochronologist Brendan Buckley’s usual occupation is drilling straw-like cores from old trees and extracting information about past climates by studying their rings. To extend the record beyond the time of living trees, he sometimes takes samples from long-dead trees, or even from timbers in ancient buildings. In 2010, the Lamont-Doherty Earth Observatory scientist was part of a team that traveled into the remote Cardamom Mountains of southern Cambodia to investigate human burials contained in coffins carved from entire logs.