Search Results

The Hudson River estuary in the United States experiences a tide from New York Harbor (river kilometer 0/river mile 0) to Troy, New York (river kilometer 244/river mile 152). In the lower 60 kilometers (37 miles) of the Hudson River, the water is…

Atmospheric ozone plays a critical role in the biosphere by absorbing harmful ultraviolet radiation in the stratosphere—the layer of the atmosphere about 10 to 50 km (6 to 30 mi) above Earth’s surface. Since the adoption of the Montreal Protocol in…

The Paris Agreement is a treaty signed by 196 member nations of the United Nations Framework Convention on Climate Change (UNFCCC) in an effort to reduce greenhouse-gas (GHG) emissions, primarily of carbon dioxide and methane, thereby limiting the…

Scientists predict that Earth’s climate will continue changing, depending in large part on the additional amount of greenhouse gases that humans emit into the atmosphere, leading to negative consequences for life on Earth. To avoid the most harmful…

Wildfires are a natural phenomenon in many ecosystems, including forests along the U.S. Pacific West Coast, as natural fires serve to rejuvenate ecological communities. However, from mid-August through mid-September 2020, forests in California,…

Microplastics are raining down on national parks and other protected areas in the western United States at the rate of about 132 pieces of microplastic per square meter every day, according to a report in the journal Science (June 2020).…

Many questions concerning the sustainable production of biofuels have emerged over recent years in terms of land and water use, pollution from fertilizer and pest-control chemicals, greenhouse-gas production, net energy production, and whether…

Obscured by a hazy atmosphere 100 times thicker than Earth's, Venus is a notoriously difficult world to study. Ground temperatures on Venus exceed 450°C (842°F)—enough to melt lead and to have quickly degraded the Soviet robotic landers last placed…

The novel coronavirus SARS-CoV-2 that emerged in central China in late 2019 and subsequently spread across the world in 2020 led to the COVID-19 pandemic. The emergence of a previously unknown pathogen—such as the novel coronavirus—that could affect…

The world’s oceans and coasts provide a natural sink for excess carbon in the atmosphere. Scientists refer to carbon that is captured and stored this way as blue carbon. Well-known blue-carbon examples include mangroves and salt marshes—wetland…

Using an artificial intelligence technique known as deep learning and high-resolution remote sensing, scientists have counted and mapped the location of trees in 11,000 satellite images covering more than 1.3 million square kilometers (500,000…

During the past decade, the automotive industry has converted more than 50 percent of its internal combustion engines from a traditional technology called port fuel injection (PFI) to a new technology called gasoline direct injection (GDI). The…

Ground-level, or tropospheric ozone (O3), is a strong oxidizing agent that reacts with living tissue. Consequently, tropospheric ozone is considered an air pollutant and a respiratory irritant at low concentrations. At higher concentrations,…

A rare and very large area of severely depleted ozone (03) opened up in the stratosphere above the Arctic Circle in March 2020. Scientists attribute this ozone hole to the persistence of a very strong polar vortex (a jet stream that circles the…

Concrete is the most widely used construction material worldwide because of its versatility, strength, and durability. Applications range from roadways and dams to furniture and tiles. With proper manufacturing, reinforcement, and engineering…

Many trees in forests worldwide rely on natural fires to create growing conditions necessary to perpetuate the ecosystem, or to stimulate germination. However, for more than 100 years, humans have been suppressing frequent natural low-intensity…

Persistent changes in the Earth's climate that have been occurring primarily as a result of human-caused greenhouse-gas emissions since the mid-twentieth century have led to significant increases in infectious diseases in wildlife, both in terms of…

Sea-level rise is caused by adding mass (water) and heat to the ocean. The Antarctic ice sheet represents a potentially large source of water. Knowing the speed and direction (velocity) at which the Antarctic ice sheet is flowing to the ocean is…

It has been a long-held belief that, as a result of hunting habits, early humans were partly or even primarily responsible for the decline and eventual extinction of most of the largest mammalian species that inhabited ancient Africa. These large…

Researchers from Rice University in Houston, Texas, United States, have found that climate change could potentially increase the size of stalled high-pressure weather systems (ridges) known as “blocking events,” according to global climate modelling…

Trees provide substantial benefits to the environment. In addition to improving air quality, reducing stormwater runoff, serving as a wildlife habitat, and sequestering carbon by absorbing carbon dioxide, trees also cool the atmosphere through shade…

Sand is mined for many applications, but the largest use by far is for fine aggregate in concrete. Smaller quantities of sand are used for fracking, water treatment (filtration), metal casting, and making glass, silicon chips, and ceramics. Concrete…

A study published in the journal Atmospheric Environment (April 2019), comparing the differences in air pollution caused by automobiles powered by internal combustion (conventional) engines versus electric vehicles (EVs) powered by batteries,…

Researchers have reached a key new milestone in the continuing search for worlds like Earth that could support life elsewhere in the universe. For the first time, water vapor has been detected in the atmosphere of an exoplanet that resides within…

Researchers surveying ice loss from 650 glaciers across a 2000-kilometer (1240-mile) west-to-east expanse of the Himalayan Mountains reported in the journal Science Advances (June 2019) significant melting caused by global climate change over the…

All freshwater comes from precipitation over land, which is distributed on Earth as blue and green water. Blue water—that is, surface and groundwater—is stored as freshwater in lakes, streams, ice, and snow, as well as below ground. Green water is…

Researchers Chi Ma of Caltech and Alan Rubin of the University of California at Los Angeles reported in the journal American Mineralogist (September 2019) the discovery in a meteorite of the first natural occurrence of the iron-carbide mineral…

Earth’s surface temperature is warming, and the Arctic region is warming even faster. Yet winters in the mid-latitudes of Asia, Europe, and the United States have been colder than average, thanks to blasts of record-breaking frigid air caused by…

After reports that June 2019 was the warmest June on record, July 2019 followed with the dubious distinction that it was the warmest month since atmospheric temperature record-keeping began in 1880, according to the U.S. National Oceanic and…

Researchers at Duke University in North Carolina (United States) have developed a test for distinguishing lead isotopes found in coal fly ash from lead isotopes found in other lead-containing sources, such as paint. Fly ash is a fine particulate…

In 1987, the Montreal Protocol, the international treaty banning chemicals that deplete the ozone layer, was adopted. Thirty years later, NASA scientists reported in the journal Geophysical Research Letters (January 2018) satellite measurements…

On August 5, 2018 at 6:46 p.m. local time, a magnitude 6.9 earthquake struck in Pulau Lombok, Indonesia. The earthquake occurred as the result of thrust faulting at a depth of 10.5 km (6.5 mi) in northern Lombok, according to the United States…

Crown-of-thorns starfish or sea stars (Acanthaster planci; order Valvatida) are predatory marine invertebrates that feed on phytoplankton found on coral. They are native inhabitants of coral reefs in both the Indian Ocean and Pacific Ocean and are…

The Mississippi River has undergone extensive river engineering for flood control, with its 3500-mile Mississippi River and Tributaries levee (artificial-embankment) system. However, researchers reported in Nature (April 2018) that disconnecting the…

The warming temperatures attributed to global climate change are making it more difficult for sea turtle populations to survive. As a result of the unusual developmental processes found in many reptiles, including some species of turtles, the sex of…

Sunscreens are polluting the ocean, and increasing evidence points toward some ultraviolet-light–absorbing chemicals found in sunscreens as being harmful to marine life—particularly corals at popular tourist destinations. While working toward…

In the fall of 2014 and early winter of 2015, an estimated 250,000 to 500,000 seabirds known as Cassin's auklets (Ptychoramphus aleuticus) died along the Pacific Coast from California to British Columbia, Canada. Researchers have now reported the…

Humans' contributions to global warming through burning fossil fuels and other actions (for example, detrimental land-use practices) have resulted in sharp increases in the levels of atmospheric carbon dioxide (CO2). These rising levels of CO2 also…

Limiting the effects of climate change to the greatest extent possible will require reducing greenhouse-gas (GHG) emissions and removing GHGs from the atmosphere. In addition, the shared goal of the countries that have entered into the Paris Climate…

By July 6, 2018, beaches on the eastern coast of St. Vincent—an island located in the southeastern Caribbean Sea (Lesser Antilles)—were covered nearly one-meter deep with rotting brown algae (seaweed), known as Sargassum, posing multiple problems…

For more than 10 years, natural-gas-fired power plants have been touted as “cleaner” electrical power generators, producing half the carbon dioxide (CO2), one-third of the nitrogen oxides (NOX), and negligible sulfur oxides (SOX) compared to…

As the global climate becomes hotter and drier, heat mitigation in urban areas through the use of cool roofs is becoming increasingly important. Cool roofs reflect more sunlight and absorb less heat than conventional roofs, according to the U.S.…

There are 27 ways a heat wave can kill you, according to a report in the American Heart Association journal Circulation: Cardiovascular Quality and Outcomes (November 2017). By 2100, at the current rate of greenhouse-gas emissions, three-quarters of…

Roman marine concrete, having lasted for nearly 2000 years, is a highly durable material. In contrast, modern marine concrete, which is made using Portland cement, may start to degrade in as few as 50 years. Researchers have now discovered why. As…

Recent excavations in Asia unearthed a pristine, three-dimensional fossil of a tiny dinosaur tail with preserved feathers and soft tissues (presumably skin). In 2016, investigators in northern Myanmar (Burma) recovered a piece of Cretaceous-era…

Global climate change affects all areas of the Earth, with some regions experiencing greater impacts than others. In particular, the Arctic treeline—that is, the southern limit of the Arctic Bioclimate Zone—is being affected to various degrees by…

Hurricane Harvey made landfall near the middle of the Texas Gulf Coast on August 25, 2017 as a Category 4 storm on the Saffir-Simpson Hurricane Wind Scale and essentially hovered over the region for seven days, unleashing heavy rain and causing…

On August 30, 2017, just as Hurricane Harvey was winding down in Texas, tropical storm Irma formed near the Cape Verde Islands located off the northwest coast of Africa and began moving west-northwest. According to the U.S. National Hurricane…

If three occurrences constitute a trend, then catastrophic storms—that is, Category 4 or 5 storms on the Saffir-Simpson Hurricane Wind Scale—are the trend for Atlantic hurricanes in 2017. One day after forming as a tropical depression, Potential…

Forests absorb and store carbon. If this ability is hampered, then levels of atmospheric carbon will increase and global temperatures will rise, leading to potentially drastic climatic changes. In particular, deforestation (the permanent elimination…

Ever since the Lusi mud volcano began erupting on May 29, 2006, in the Porong subdistrict of Sidoarjo in East Java, Indonesia, scientists have been unable to agree on its cause. Two days before to the eruption, two events occurred—a magnitude 6.3…

Mangrove forests are taxonomically diverse assemblages of trees and shrubs that form the dominant plant communities in tidal, saline wetlands along sheltered tropical and subtropical coasts. They have several ecological and physical functions that…

Tornado warnings save lives. In order to save lives, however, tornado warnings—issued when a tornado has been sighted or identified by Doppler radar—need to be early and accurate. According to the U.S. National Oceanic and Atmospheric Administration…

In an attempt to quantify the amount of plastics ever produced and what has happened to them, researchers produced the first global analysis using data collected from plastic industry sources. As reported in Science Advances (July 2017), 8300…

Two major earthquakes struck Mexico, a seismically active country, within two weeks in September 2017. The first and strongest earthquake occurred off the southern Pacific coast of Mexico and the second earthquake occurred 11 days later in central…

Research into the depleted state of the Great Barrier Reef, one of the great wonders of the natural world, provides a vivid case study of the extreme harm that the warming climate and the affliction called coral bleaching cause globally. In March…

Arctic sea-ice cover has been steadily thinning for years, according to satellite measurements since 1979. In March 2017, when ice cover should have been near its maximum, the U.S. National Snow and Ice Data Center reported that Arctic sea-ice…

Wildfires are known to emit large amounts of gaseous and particulate pollutants. In an effort to identify and quantify these pollutants, researchers took their instruments to the skies where they sampled and analyzed smoke plumes from aircraft…

A magnitude 5.1 nuclear test was detected 376 km (234 mi) NE of Pyongyang, North Korea (DPRK) on January 6, 2015 at 10:30 a.m. local time (01:30 UTC), according to the U.S. Geological Survey (USGS). The event was picked up at seismic stations around…

A powerful magnitude 7.8 earthquake struck Ecuador on April 16, 2016 at 6:58 p.m. local time, causing extensive damage to buildings and infrastructure as well as hundreds of fatalities and thousands of injuries. The epicenter was located 52.0 km…

High within the coldest and driest continent, Antarctica, lies what may be an environment too hostile to support life, according to a team of scientists from Canada and the United States. They reported finding no evidence of microbial life in the…

When volcanoes erupt explosively, they can hurl huge ash plumes of fine (<2 mm) glassy and jagged rock and mineral fragments into the atmosphere. The smallest of these ash particles, less than 200 micrometers across, can travel hundreds of…

A regional or local tsunami warning system that uses both seismic and GPS stations could broadcast more prompt and accurate tsunami warnings and could potentially reduce casualties in the event of a major earthquake, according to a report in…

Groundwater is the most abundant source of freshwater for drinking and irrigation. It is a renewable resource that is stored in underground reservoirs (aquifers) and replenished by precipitation. Withdrawing groundwater faster than it is replenished…

In a rare winter occurrence, a North Atlantic hurricane, named Alex, attained Category 1 strength on the Saffir-Simpson hurricane wind scale in January 2016. Alex is only the second Atlantic hurricane known to have formed in the month of January.…

Most lakes worldwide are warming, according to a survey of lake summer surface water temperatures (LSSWT) released in late 2015, the most comprehensive of its kind to date. Using both satellite and ground-based data obtained from 1985 to 2009 for…

Between 2004 and 2014, the total phosphorus content of lakes and streams in the contiguous (lower 48) United States rose, according to surveys by the U.S. Environmental Protection Agency (EPA) reported in the journal Environmental Science &…

On April 29, 2015, the U.S. Geological Survey (USGS) reported five earthquakes in Oklahoma of magnitude 2.5 or greater—that is, tremors strong enough to be felt. The most powerful of these was a M4.1 earthquake 21 km (13 mi) west of the city of…

On April 25, 2015 at 11:56 a.m local time, a magnitude 7.8 earthquake struck in the district of Lamjung, approximately 80 km northwest of Kathmandu, Nepal. The earthquake occurred as the result of thrust faulting [15.0 km (9.3 mi) in depth] in the…

For nearly 50 years, marine chemists have generally accepted that when microscopic organic compounds in seawater, known as dissolved organic carbon (DOC), sank into the deep ocean below 1000 m in depth, they became resistant to microbial…

Much of coastal and southern California has a Mediterranean climate, which is characterized by cooler, wetter winters and hotter, drier summers. Only drought-resistant plant species can survive without irrigation in this type of climate. Turf grass,…

Researchers from the University of Washington took advantage of the six-month-long Bárdarbunga-Veidivötn fissure eruption in Iceland, from August 31, 2014 to February 28, 2015, to investigate the effect of its sulfur dioxide (SO2) emissions on cloud…

Since 1975, approximately 1200 dams have been removed from rivers in the United States, including 72 in 2014. Some of these dams were in danger of failure, others had become functionally obsolete because their reservoirs had filled with sediment,…

Glacial earthquakes are moderate (roughly magnitude 5) seismic events that occur when ice flowing to the ocean from large glaciers, or ice sheets, breaks off (calves). They were discovered in 2003 by Göran Ekström and coworkers as an anomalous…

Over a 21-hour period from October 22 to 23, 2015, Hurricane Patricia strengthened from a Category one to a Category five storm on the Saffir-Simpson hurricane wind scale, breaking a number of meteorological records along the way prior to slamming…

For years, protecting shorelines from flooding and erosion was managed by installing "hard" structures such as concrete retaining walls known as bulkheads and seawalls. Bulkheads, for example, are intended to prevent erosion by holding back the…

On August 29, 2015, three major hurricanes were active over the Pacific Ocean at the same time—a meteorological first. According to the National Oceanic and Atmospheric Administration’s (NOAA) National Hurricane Center, a major hurricane has wind…

One of the most remarkable features of the sea (marine) turtles that inhabit the tropical and subtropical waters of the world is their homing ability. Throughout the year, sea turtles swim huge distances, often more than 1600 kilometers (1000…

On September 16, 2015 at 7:54 p.m. local time, a magnitude 8.3 earthquake struck approximately 229 km (142 mi) NNW of Santiago, the capital of Chile. The earthquake occurred as the result of thrust faulting [25.0 km (15.5 mi) in depth] between the…

Over a period of 14 days, from October 28, 2015 to November 10, 2015, two tropical cyclones formed and traversed the Arabian Sea, taking nearly identical paths and bringing hurricane-strength winds and abundant rainfall to Yemen and its island of…

On August 3, 2015, President Barack Obama announced in a White House ceremony the U. S. Environmental Protection Agency’s (EPA) Clean Power Plan (CPP) for reducing carbon dioxide (CO2) emissions from the country’s stationary fossil-fuel power…

The “Blob" is the name given by Nicholas Bond of the University of Washington to an area of unusually warm water off the Pacific Northwest of North America (Gulf of Alaska). It was first detected by satellite imagery in the fall of 2013 as an…

A recently discovered group of crustaceans called yeti crabs (genus Kiwa, order Decapoda) have added to the number of extraordinary and previously unknown species inhabiting the harsh, inhospitable environment around hydrothermal vents on the deep…

Sinkholes form when surface sediments collapse, sometimes dramatically, into a cavity below. They can be an unintended consequence of human activity. For example, on May 22, 2014, after a water main burst on the Lower East Side of New York City, the…

Europa, one of the four largest natural satellites, or moons, orbiting the planet Jupiter, may be the first planetary body in the solar system other than Earth to show evidence of plate tectonics, a research team from the University of Idaho and…

Perhaps the most mysterious and sought-after of all ocean creatures, the giant squid Architeuthis dux was finally captured on video in its natural habitat in July 2012 during an expedition off the coast of the Ogasawara archipelago of Japan. The…

The Earth’s core consists of a solid inner and a fluid outer region and extends from a depth of about 2900 km (1800 mi), the lower edge of the mantle, to about 6400 km (3800 mi), the center of the planet. At about 5100 km (3100 mi) down, the core is…

Every year, landslides claim thousands of lives and cause considerable economic damage to buildings, roads, and other infrastructure around the world. As natural hazards, landslides are largely unpredictable. Improvements in the monitoring,…

The Madden-Julian oscillation (MJO), also known as the tropical intraseasonal oscillation, is a cyclic weather pattern (wave) that travels from west to east along the equator every 30–90 days. The MJO, discovered by in 1971 by Roland Madden and Paul…

The U.S. Geological Survey published a new and extraordinarily detailed global geologic map of Mars on July 14, 2104, based on remotely sensed image and topographic data gathered over 16 years by four orbiting spacecraft: Mars Global Surveyor…

Soil organic matter represents a reservoir of stored (sequestered) carbon that slowly cycles between the earth and the atmosphere. It is predominately composed of humus stabilized by clay particles, with the remainder being less stable decaying…

When the Whitney Museum of American Art opens its new building in downtown New York City in 2015 it will have watertight doors and glass on the ground level as well as a temporary flood barrier that can be quickly assembled around its perimeter. Of…

In Southwestern Australia, drought is the new norm. Rainfall there has been below average since 2012 and yearly averages have been dropping since 1970. Researchers from the National Oceanic and Atmospheric Administration (NOAA), using a new and…

On May 24, 2013 at 3:44 p.m. local time, a magnitude 8.3 earthquake struck deep below the Sea of Okhotsk about 406 km west-northwest of Petropavlovsk-Kamchatskiy, Russia. The earthquake occurred as the result of normal faulting at a depth of 609 km,…

Since the early 1950s, the U.S. National Weather Service’s Storm Prediction Center has been collecting tornado data. From 1952 to 2011, there has been a steady increase in the total number of tornadoes reported in the United States annually, largely…

Until recent years, the research focus on the high-energy photons known as gamma rays has been on nuclear and cosmic sources for them. Now it has moved to the cloud—the thundercloud, that is—where short bursts of gamma rays, known as terrestrial…