Earth Bulletin

As the leading greenhouse gas, carbon dioxide is one of the atmosphere’s most closely watched ingredients. The scrutiny began in 1958, when a young geochemist named Charles Keeling began regularly measuring CO2 atop a massive Hawaiian volcano—and discovered some intriguing patterns.

As seismic waves from earthquakes pass through the planet, their patterns can reveal hidden dynamics—hotspots, deep-diving rock, melting mantle—in Earth’s interior. An array of seismometers that’s being installed across the United States is now allowing geophysicists to plot revelatory views of the Earth engine deep beneath our feet.

Every September and October, a “hole” of varying size emerges in Earth’s ozone layer over Antarctica, an effect of a buildup of ozone-depleting human-made chemicals high in the atmosphere. Now that levels of these chemicals are declining as a result of international agreements put in place decades ago, scientists predict that the annual ozone hole is poised to begin a shrinking trend.

With more than 160 million people living in a space a little larger than Iowa, Bangladesh is the most crowded country on Earth. It also straddles several tectonic plate boundaries, leaving the landscape at high risk for earthquakes. This Bulletin follows geologists as they map a major fault near the capital, Dhaka, and study how a shift on that fault could move a major river through the populous region.

As climate change progresses, the seasonal ice covering the Arctic Ocean is becoming not only less extensive but also much younger and thinner. Watch recent, dramatic changes in sea ice in this data visualization.

What are humans to do with the billions of tons of carbon dioxide we release into the atmosphere? Since 1996, an experiment in the North Sea has been injecting millions of tons of excess carbon dioxide captured from natural gas drilling back into the Earth for safe storage. The technology is gaining ground as a viable innovation to help combat climate change.

Analysis of Earth’s geologic record can reveal how the climate has changed over time. Scientists in New Zealand are examining samples from the rocky landscape once dominated by glaciers. They are employing a new technique called surface exposure dating, which uses chemical analysis to determine how long minerals within rocks have been exposed to the air since the glaciers around them melted. Comparisons of this data with other climate records have revealed a link between glacial retreat and rising levels of carbon dioxide in the air, findings that are informing scientists’ understanding of global climate change today.

Texas suffered its driest year ever in 2011, and southern Alabama and Georgia have continued to suffer serious drought in 2012. Climate change is predicted to make drought more frequent in the southern United States, putting a strain on groundwater reservoirs. This visualization reveals the freshwater stores that NASA’s GRACE (Gravity Recovery and Climate Experiment) satellite detects from space and shows how that data can be used to evaluate groundwater gains and losses, critical information in the effort to conserve the water that people depend upon.

The heat stored in the ocean influences the atmosphere above, impacting weather and climate around the globe. Long-term satellite observation of the ocean’s surface temperatures enables scientists to understand large-scale climate patterns. One such pattern is the El Niño/Southern Oscillation, or ENSO, cycle, marked by the changing temperature of surface waters in the equatorial Pacific Ocean. In 2010, one phase of the ENSO cycle—El Niño—shifted dramatically to La Niña, its opposite phase. You can watch the shift and the wild weather that resulted in this visualization of sea surface temperature data.

In November 2010, ten months after a magnitude 7.0 earthquake flattened huge sections of Port-au-Prince, Haiti, a team of geologists commissioned by the United Nations set out to make the first detailed soil map of the city. Armed with sledgehammers and vibration sensors, the scientists surveyed how soils throughout Port-au-Prince either amplify or muffle seismic vibrations. The resulting map can now be used to guide reconstruction efforts. In this Science Bulletins feature, learn how geologists and engineers in Haiti and San Francisco are improving our resilience to powerful shifts of Earth's crust.

Scientists in Sicily are collecting an enormous amount of data to monitor moving magma inside Mount Etna, one of the most active volcanoes in the world. Nearly a million people live on the volcano’s flanks, so being able to predict an eruption could be a matter of life and death. In this Earth Bulletin, visit the volcano’s snowy slopes and learn how scientists from the Italian National Institute for Geophysics and Volcanology record seismic activity, measure gases seeping up through the ground, sense the volcano’s temperature changes, and assess disturbances in gravitational and magnetic fields to predict eruptions weeks ahead of time.

Zircons are minerals that typically exist as tiny crystals in rocks. Though they are small, they have a big story to tell. Some zircon crystals are the oldest Earth materials ever discovered, and they reveal clues about periods of geological time for which there is no direct evidence. Almost entirely as a result of studies of zircons, scientists are developing new hypotheses about what Earth’s first 500 million years may have been like. Travel to a remote island off Greenland’s coast and a zircon-making lab in New York State to learn how geologists are finding and understanding these time capsules.

Fifty-five million years ago, a sudden, enormous influx of carbon flooded the ocean and atmosphere for reasons that are still unclear to scientists. What is clear is that as atmospheric CO2 content increased, the average global surface temperature rose 5°C to 9°C (9°F to 16°F). The Paleocene-Eocene Thermal Maximum (PETM), as this global warming event is known, lasted upwards of 170,000 years and had dramatic impacts on living things both on land and in oceans. In this feature, a team of paleontologists, paleobotanists, soil scientists, and other researchers take to the field in Wyoming's Bighorn Basin to document how the climate, plants, and animals there changed during the PETM. Their work will help predict how our current global warming event could affect life on Earth.

One paradox of geology is that weathering a mountain down can actually make it rise higher. Scientists have learned of this peculiar feedback process only in recent years, and the St. Elias Erosion/tectonics Project (STEEP) team is at the forefront of understanding how climate and the movements of Earth’s crust interact to build towering peaks. In this feature video, meet geologists of every stripe collaborating on STEEP in Alaska’s St. Elias Range, one of the most rapidly growing mountain ranges in the world.

The Basin and Range Province is a dramatic landscape covering much of the southwestern United States. Its star attraction is Death Valley, a below-sea-level desert basin flanked by mountain ranges rising as high as 3.6 kilometers. This story covers a team of geologists who are combining traditional fieldwork with animated computer modeling to understand how the Basin and Range’s geological drama has played out over the past 36 million years.

The rising temperatures of global climate change are melting the world’s ice. Most notable are the shrinking ice sheets of Greenland and west Antarctica, which have shown dramatic loss in recent years. Travel to the glaciers of Greenland and to fossilized coral reefs of the Florida Keys, where earth scientists are studying geologic records of past warming to predict future ice loss and associated sea level rise.

Three of the most catastrophic volcanic eruptions in geologic history occurred at a place now visited by nearly four million people a year: Yellowstone National Park. The magma chamber responsible still lies beneath, and continues to steam, heat, and shift the park landscape. Science Bulletins talks with the geologists regularly monitoring these disquieting signals to understand where this active region lies in its volcanic life span.

The scientific data left in the wake of the horrific December 26, 2004 tsunami is proving invaluable to better prepare for future events. Meet the researchers at the crest of this relatively young science. Featured are the geologists, seismologists, and computer modelers of the U.S. Pacific Northwest, an area replete with geological and anthropological evidence of past tsunamis. Learn how the region is preparing for its inevitable next wave.

Follow scientist-adventurer Lonnie Thompson to the 5,670-meter-high Quelccaya ice cap in the Peruvian Andes. Thompson and his team from Ohio State University are racing to core a cylinder of 1,500-year-old ice to unravel the past climate patterns of this region - before our gradually warming climate melts this invaluable record away. By analyzing global ice cores, glaciologists like Thompson now have a well-preserved record for 150,000 years of climate history, allowing us to better predict future climate change.

For centuries, a massive atmospheric system has regularly altered weather patterns, fishery production and animal migrations across the North Atlantic Ocean. At last, Earth scientists and climate modelers are beginning to understand how--and when - the North Atlantic Oscillation happens.

Follow geologists as they hunt for, pick axe, and test rock samples from the 2.5 billion year old Huronian Supergroup, a sedimentary formation in Ontario, Canada. The scientists are in search of an exact record of how much oxygen gas Earth's developing atmosphere contained at key moments in geologic time. These crustal relics, which have interacted directly with ancient atmospheres, have the power to tell scientists when and how the Earth built up its incredible life-support system to foster more and more complex organisms.

On July 4, 1999, a rare and terrifying storm swept through the Boundary Waters Canoe Area Wilderness in northern Minnesota. What began like a standard-issue thunderstorm soon turned strange and fierce, generating green clouds and strong winds reminiscent of a tornado. In fact, the storm was a cousin of the tornado: a derecho (pronounced "de-RAY-cho"), a type of storm so infrequent and fast-moving that only in recent years have meteorologists begun to understand how to recognize and forecast it. This feature tells the story of this unusual event and the efforts of scientists to understand it.

In recent years, scientists have begun using satellite technology to study earthquakes from space. By monitoring the tiniest movements of the Earth's crust, they are zeroing in on places where strain is building up and the crust will most likely snap. These efforts could help California residents protect the areas at greatest risk before the next big quake strikes.

In 1980 an act of Congress set aside nearly 20 million acres of Alaska's North Slope tundra to create the Arctic National Wildlife Refuge (ANWR). Less than 100 miles from the refuge is Prudhoe Bay, North America's largest oil field. Spread across what was once part of the largest intact wilderness area in the United States, Prudhoe Bay and its neighboring oil fields account for approximately 25 percent of U.S. domestic oil production.