River Steaming

Steaming river of black sludge floods through Arizona –

A screenshot shows the rush of the debris flow down the trail.

A screenshot shows the rush of the debris flow down the trail.

(Image: © Pima County)

A camera points down a seemingly benign trail in Pima County, Arizona. But just moments into the video, something dark appears in the distance, before blanketing the dry dirt. Eventually, it resolves into a coal-black river of sticks and sludge, flowing almost as quickly as clear water.

The video, posted to Twitter by Pima County officials, shows a July 15 debris flow following a wildfire at Cañada del Oro Wash — a drainage channel and mountain biking trail in the county. According to the U.S. Geological Survey (USGS), fires can change the way rainwater flows over land. Under normal circumstances, most dirt is capable of sucking up a lot of water, which keeps flash floods from happening every time it rains. But after a wildfire, the land is no longer able to absorb as much water. And even minor rains can trigger flash floods filled with debris.

Who had this on their 2020 hellscape bingo card? 16, 2020

“Fast-moving, highly destructive debris flows triggered by intense rainfall are one of the most dangerous post-fire hazards,” according to USGS’s California Water Science Center. “It takes much less rainfall to trigger debris flows from burned basins than from unburned areas. In Southern California, as little as 7 millimeters (0.3 inches) of rainfall in 30 minutes has triggered debris flows.”

In 2018, mudslides and debris flows after the Thomas Fire killed 13 people in two California towns after a winter storm, according to Santa Barbara Family Life

I just got back from this exact location to check and see how the wash looks today… Officials are saying this year, the flood risk is higher due to the #BighornFire.Thanks to Billy, a nearby resident, who gave me permission to enter the area! @KVOA 17, 2020

According to KGUN 9, a local news station, this recent debris flow seems to have originated with the Bighorn Fire, which has burned about 120,000 acres (485 square kilometers) in the area.

No casualties or major damage have been reported from this event, despite the dramatic footage. But the risk of heavy, debris-filled floods of this kind remains for years after a fire, according to the USGS. The largest such events usually happen in the first storm season after a major fire.

To avoid major post-fire debris disasters, the USGS examines burned regions for potential risks and sets up flood gauges to provide emergency alerts if floodwaters rush past.

As the climate changes, wildfires have become more common all over the world, bringing with them all sorts of risks, according to NASA. Research published in June by the National Bureau of Economic Research suggests wildfires burn four times more land each year in the United States than they did 40 years ago.

Originally published on Live Science.

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monster' River

‘River monster’ first-known dinosaur to have lived in water – BBC Focus Magazine

The newly-discovered tail fossil of the first “river monster” dinosaur shows the giant predator was a powerful swimmer and the first known to have lived in the water.

The six-tonne Spinosaurus aegyptiacus prowled the rivers that flowed through the Sahara desert 100 million years ago, living and catching its prey in the water, according to the new research.

The study on the tail, which was unearthed in southern Morocco, was carried out by an international team including from the universities of Portsmouth and Leicester, and supported by a grant from the National Geographic Society.

'River monster' first-known dinosaur to have lived in water (Reconstruction of Spinosaurus in life © Davide Bonadonna/PA)
Reconstruction of Spinosaurus in life © Davide Bonadonna/PA

The University of Portsmouth said: “Until now it was believed that dinosaurs lived exclusively on land, but the newly discovered tail of Spinosaurus aegyptiacus, a giant predator, shows that it was actually well adapted to an aquatic lifestyle.

“The 15-metre-long, six-tonne predator was, in fact, a powerful swimmer propelled by a huge fin-like tail, which hunted down its prey in vast river systems that flowed through the Sahara desert 100 million years ago.

“It is the first time that such an adaptation has been reported in a dinosaur.”

Top: reconstruction of the tail skeleton of Spinosaurus (missing bones shown in white). Centre: cross sections through the tail showing changes in the vertebrae, tail volume, and arrangement of major muscles. Bottom: the new, surprising look of Spinosaurus (black, soft parts; red, bones collected by the locals; green, bones from recent scientific excavations; yellow, bone fragments collected in the debris). Drawings: Marco Auditore. (Gabriele Bindellini/PA)
Reconstruction of the  Spinosaurus tail skeleton (missing bones shown in white), cross sections through the tail and a complete view of Spinosaurus © Marco Auditore/Gabriele Bindellini/PA

Dr David Unwin, reader in palaeobiology at the University of Leicester, said: “The Spinosaurus’ fin-like tail is a game-changing discovery for us that fundamentally alters our understanding of how this dinosaur lived and hunted – it was actually a ‘river-monster’.

“As well as its tail, many other features of this dinosaur, such as the high position of the nostrils, heavy bones, short legs, and paddle-like feet point to a life spent in the water rather than on land.

“Not only did dinosaurs dominate the land and take to the air as birds, they even went back into the water and became the top predators there as well.”

'River monster' first known dinosaur to have lived in water (Two Spinosaurus hunt Onchopristis, a prehistoric sawfish, in the waters of the Kem Kem river system in what is now Morocco © Jason Treat, NG Staff, and Mesa Schumacher Art: Davide Bonadonna Source: Dr. Nizar Ibrahim, University of Detroit Mercy)
Two Spinosaurus hunt Onchopristis, a prehistoric sawfish, in the waters of the Kem Kem river system in what is now Morocco © Jason Treat, NG Staff, and Mesa Schumacher, Art: Davide Bonadonna, Source: Dr. Nizar Ibrahim, University of Detroit Mercy)

The Portsmouth spokeswoman said: “The team found that in place of a stiff tapering tail, typical of other theropod dinosaurs such as the Tyrannosaurus Rex, the tail vertebrae of Spinosaurus had extraordinarily long spines that supported a large, highly flexible, fin-like tail comparable in shape to that of a crested newt.

“After preparing all the fossils, the team used photogrammetry to digitally capture the anatomy of the tail.

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“To quantitatively assess the performance of the tail, a team of Harvard researchers made a flexible model of the tail and attached it to a robotic system that mimics swimming movements.

“They then compared the swimming performance of the Spinosaurus tail to model tails from other animals, including dinosaurs, crocodiles and newts.

“The results are fully consistent with the idea of a truly water-dwelling, tail-propelled, ‘river monster’.”

Reconstruction of Spinosaurus (University of Portsmouth/PA)
Reconstruction of Spinosaurus © University of Portsmouth/PA

Professor David Martill, professor of palaeobiology at Portsmouth, said: “One thing that still puzzles me though, is why only Spinosaurus became aquatic among the dinosaurs. Why are there no aquatic iguanodons, or stegosaurs?”

Paleontologist Dr Nizar Ibrahim, of the University of Detroit Mercy and a National Geographic Explorer, said: “This discovery is the nail in the coffin for the idea that non-avian dinosaurs never invaded the aquatic realm.”

The research was published in the journal Nature.

Reader Q&A: What was the first dinosaur?

Asked by: Adam King, Huddersfield

As palaeontologists uncover more fossils around the world, we keep finding new dinosaurs from the Triassic Period: the first interval of dinosaur history.

Currently, the oldest known dinosaurs come from Argentina, and they’re about 231 million years old. There are several dinosaurs of this age found together, including the horse-sized meat-eater Herrerasaurus, the dog-sized meat-eater Eodromaeus (a distant relative of T. rex), and several dog-to-bear-sized cousins of the giant long-necked sauropods, including Panphagia and Eoraptor.

The fact that so many dinosaurs, with different diets and sizes, lived at this time tells us that dinosaurs were already diversifying soon after they evolved from other reptiles. But none of these dinosaurs were giants, and none were at the top of the food chain. Those species would come later, during the Jurassic Period.

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Alexander McNamara

Alexander is the Online Editor at BBC Science Focus and is the one that keeps looking shipshape and Bristol fashion. He has been toying around with news, technology and science on internet for well over a decade, and sports a very fetching beard.

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