Taxonomy term

sediment

Red Planet Roundup: April 2017

With two rovers patrolling the surface of Mars, six spacecraft orbiting above it, and scientists here on Earth studying the Red Planet from afar, new findings are announced often. Here are a few of the latest updates.

 
14 Apr 2017

Supernova explosion detected in Early Pleistocene sediments

When a massive star comes to the end of its life cycle, it goes out with a spectacular bang known as a supernova. Only three of these events have been observed in the Milky Way in the past 1,000 years. Evidence for older explosions can be detected in the form of rare elements found on Earth that are only produced by such explosions.

10 Jan 2017

Frosted forams foil radiocarbon dating

Climate studies often rely on radiocarbon dating of tiny shells in seafloor sediments to pinpoint the timing of when warming or cooling events began and ended. But a new study indicates that chemical reactions that take place on the seafloor may affect the accuracy of such radiocarbon dates, with potential implications for the dates published by past studies

01 Nov 2016

Dating of landslides around Oso reveals recurring patterns

On March 22, 2014, after a period of heavy rain, a hillside near the town of Oso, Wash., collapsed, sending 7.6 million cubic meters of mud and debris across the North Fork of the Stillaguamish River, destroying a rural neighborhood and killing 43 people. The slide took Oso residents by surprise, but scientists say the event was not altogether unexpected, as evidence for dozens of past landslides can be found throughout the Stillaguamish River Valley. New research suggests that large slides have occurred in the Oso vicinity even more frequently than previously suspected.

07 Jun 2016

Lake sediments suggest mild volcanic winter after massive Toba eruption

Roughly 74,000 years ago, the largest volcanic eruption of at least the last 2.5 million years — and possibly the last 27 million years — spewed as much as 5,000 cubic kilometers of magma and ash, the latter of which spread far and wide from the source. This catastrophic eruption of the Toba supervolcano on the Indonesian island of Sumatra has long been suggested as a trigger for a precipitous period of global cooling known as a “volcanic winter” that in turn might have driven early humans to the brink of extinction. In a new study, researchers dispute these notions, concluding from an analysis of climate-sensitive microfossils preserved in lake sediments in East Africa — the ancestral home of early humans — that the region experienced little or no cooling following the massive eruption. 
 
10 Jan 2016

Oceanographers solve mysterious beach explosion

Late on the morning of Saturday, July 11, 2015, Kathleen Danise, a 60-year-old nurse and grandmother from Waterbury, Conn., was enjoying a sunny day at Salty Brine State Beach on the shores of Block Island Sound in Narragansett, R.I., when an explosion knocked her from her beach chair. She landed a few meters away near a rock jetty, unconscious and suffering a concussion, two fractured ribs and bruising for which she was hospitalized overnight.
 
29 Dec 2015

Subseafloor biosphere extended to greatest depth yet

Scientists studying sediments collected from the deepest scientific borehole ever drilled have found microorganisms living at astounding depths beneath the seafloor. Recent studies have previously found bacteria and archaea scratching out meager livings in marine sediments buried as deep as 1.9 kilometers, but the new find extends the known biosphere even farther down.
 
22 Dec 2015

Ancient floods degassed Lake Kivu

The deep, cold waters of Lake Kivu — a stratified volcanic lake in the East African Rift Valley on the border of Rwanda and the Democratic Republic of the Congo — hold 300 cubic kilometers of carbon dioxide gas and 60 cubic kilometers of methane, which seep from magmatic sources below the lake. An overturning of the thermally stratified waters could release those deadly gases onto a population of nearly 2 million.
 
16 Sep 2015

Sediment load shapes rivers

The amount of sediment carried in meandering rivers influences how quickly the bends in those rivers migrate back and forth, according to recent research in Nature Geoscience addressing a longstanding question regarding river evolution. Meanders form when flowing water erodes one riverbank while simultaneously depositing sediment on the opposite bank, gradually creating more and more pronounced U-shaped bends. Sometimes, the rivers cut new channels across the narrow necks of such bends, isolating the abandoned meanders to form distinctive oxbow lakes. 
 
04 Jul 2015

Kamikaze typhoons spared Japan from Kublai Khan

Like any good conqueror, Kublai Khan just wanted to expand his empire. So in the late 13th century, the grandson of Genghis Khan launched a mythic fleet to seize control of Japan. According to Japanese legend, however, the Mongol ships met with typhoons of equally mythic proportions, which quashed their repeated invasions — twice.

01 Apr 2015

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