Tuff Schist

The adventures of an unstable geologist

14 notes

tangledwing:

Nature’s coast guards

Barrier islands aren’t just for beach vacations — they protect coasts from storms and flooding.The United States has more than 400 barrier islands. That’s the most of any country. More than 1.4 million Americans live on barrier islands. Millions more visit them, especially in summer. Some barrier islands are famous for their vacation resorts, such as Fire Island in New York; Long Beach Island in New Jersey; North Carolina’s Outer Banks; Sanibel and Captiva islands in Florida; and South Padre Island in Texas. Other barrier islands have gained renown as parks and nature reserves that protect wildlife.But the biggest value that barrier islands offer is their ability to shield coastlines from the punishing force of ocean storms.Wind, waves and currents form and erode barrier islands. Although these islands can last for thousands of years, many today face serious threats. Key to their survival is the ability of these islands to shift and move in response to wind and waves. But when people cover barrier islands with roads, parking lots and buildings, they block the natural flow of sand. And that makes these islands erode more easily.Meanwhile, changes to the flow of onshore rivers have cut off the supply of sediments that replenish barrier islands. With global warming, sea levels have been rising. This means that with every wave, more water washes onto barrier islands. Scientists have also linked rising global temperatures to more and stronger ocean storms. So winds and waves strike the islands with more force, causing more damage.

tangledwing:

Nature’s coast guards

Barrier islands aren’t just for beach vacations — they protect coasts from storms and flooding.

The United States has more than 400 barrier islands. That’s the most of any country. More than 1.4 million Americans live on barrier islands. Millions more visit them, especially in summer. Some barrier islands are famous for their vacation resorts, such as Fire Island in New York; Long Beach Island in New Jersey; North Carolina’s Outer Banks; Sanibel and Captiva islands in Florida; and South Padre Island in Texas. Other barrier islands have gained renown as parks and nature reserves that protect wildlife.

But the biggest value that barrier islands offer is their ability to shield coastlines from the punishing force of ocean storms.

Wind, waves and currents form and erode barrier islands. Although these islands can last for thousands of years, many today face serious threats. Key to their survival is the ability of these islands to shift and move in response to wind and waves. But when people cover barrier islands with roads, parking lots and buildings, they block the natural flow of sand. And that makes these islands erode more easily.

Meanwhile, changes to the flow of onshore rivers have cut off the supply of sediments that replenish barrier islands. With global warming, sea levels have been rising. This means that with every wave, more water washes onto barrier islands. Scientists have also linked rising global temperatures to more and stronger ocean storms. So winds and waves strike the islands with more force, causing more damage.

971 notes

migeo:

Stromatolites (by mrfuller)
These are the oldest lifeforms on Earth, existing for over 3.5 billion years. This is a UNESCO heritage site and one of the only places in the world to find living stromatolites. And they don’t mind the heat: It was 47˚C when I took this.

migeo:

Stromatolites (by mrfuller)

These are the oldest lifeforms on Earth, existing for over 3.5 billion years. This is a UNESCO heritage site and one of the only places in the world to find living stromatolites. And they don’t mind the heat: It was 47˚C when I took this.

10,600 notes

fuckyeahfluiddynamics:

In the dark of the ocean, some animals have evolved to use bioluminescence as a defense. In the animation above, an ostracod, one of the tiny crustaceans seen flitting near the top of the tank, has just been swallowed by a cardinal fish. When threatened, the ostracod ejects two chemicals, luciferin and luciferase, which, when combined, emit light. Because the glow would draw undesirable attention to the cardinal fish, it spits out the ostracod and the glowing liquid and flees. Check out the full video clip over at BBC News. Other crustaceans, including several species of shrimp, also spit out bioluminescent fluids defensively. (Image credit: BBC, source video; via @amyleerobinson)

fuckyeahfluiddynamics:

In the dark of the ocean, some animals have evolved to use bioluminescence as a defense. In the animation above, an ostracod, one of the tiny crustaceans seen flitting near the top of the tank, has just been swallowed by a cardinal fish. When threatened, the ostracod ejects two chemicals, luciferin and luciferase, which, when combined, emit light. Because the glow would draw undesirable attention to the cardinal fish, it spits out the ostracod and the glowing liquid and flees. Check out the full video clip over at BBC News. Other crustaceans, including several species of shrimp, also spit out bioluminescent fluids defensively. (Image credit: BBC, source video; via @amyleerobinson)

(via damnneptune)

721 notes

utcjonesobservatory:

You Can Now Access All Of Richard Feynmans Physics Lectures For Free: 
 
The lectures of Nobel Prize winning physicist Richard Feynman were legendary. Footage of these lectures does exist, but they are most famously preserved in The Feynman Lectures. The three-volume set may be the most popular collection of physics books ever written, and now you can access it online, in its entirety, for free.
The complete online edition of The Feynman Lectures on Physics has been made available in HTML 5 through a collaboration between Caltech (where Feyman first delivered these talks, in the early 1960s) and The Feynman Lectures Website. The online edition is “high quality up-to-date copy of Feynman’s legendary lectures,” and, thanks to the implementation of scalable vector graphics, “has been designed for ease of reading on devices of any size or shape; text, figures and equations can all be zoomed without degradation.”
Volume I deals mainly with mechanics, radiation and heat; Volume II with electromagnetism and matter; and Volume III with quantum mechanics.
Go. Have fun. 
[The Feynman Lectures on Physics via Open Culture]

utcjonesobservatory:

You Can Now Access All Of Richard Feynmans Physics Lectures For Free:

 

The lectures of Nobel Prize winning physicist Richard Feynman were legendary. Footage of these lectures does exist, but they are most famously preserved in The Feynman Lectures. The three-volume set may be the most popular collection of physics books ever written, and now you can access it online, in its entirety, for free.

The complete online edition of The Feynman Lectures on Physics has been made available in HTML 5 through a collaboration between Caltech (where Feyman first delivered these talks, in the early 1960s) and The Feynman Lectures Website. The online edition is “high quality up-to-date copy of Feynman’s legendary lectures,” and, thanks to the implementation of scalable vector graphics, “has been designed for ease of reading on devices of any size or shape; text, figures and equations can all be zoomed without degradation.”

Volume I deals mainly with mechanics, radiation and heat; Volume II with electromagnetism and matter; and Volume III with quantum mechanics.

Go. Have fun.

[The Feynman Lectures on Physics via Open Culture]

166 notes

itssedimentary:

END-PERMIAN (250 Ma) - “The Great Dying”
Severity: 1st worst
Cause: Eruption of Siberian Traps
Climate: Cold to extremely warm; ocean acidification and anoxia, ozone destruction
Aftermath: Permanent ecosystem reorganization; low O2 for >106 years
There’s good reason why the End-Permian extinction is referred to as “The Great Dying”; 95% of all marine families, 53% of all marine families, 84% of marine genera, and 70% of known land species went extinct,
The extinction likely occurred in three stages:1. Land extinctions over ~40,000 yrs2. Very abrupt marine extinctions3. Second phase of land extinctions
Calcifying marine organisms such as brachiopods and bryozoa were the hardest hit, representative of ocean acidification. The last of the Cambrian fauna also died off, and this was the only known mass extinction of insects
So what exactly made the End-Permian extinction so severe? There truly was a perfect storm to make this the deadliest million years in Earth’s history.
Earth had been emerging from a moderate ice age when the largest flood basalt event in history (the Siberian Traps) occurred, which released vast amounts of CO2. The oceans then became increasingly warm, acidic, stratified, and euxinic from decaying organic matter. The atmosphere also became flooded with light (biogenically fixed) C, possibly from seafloor methane hydrates or from coal gas released as a result of heating from the Siberian Traps. Greenhouse gases soon caused global temperatures to spike, leading to massive extinction. Global euxinia in the oceans then became a severe problem, with sulfate reducing bacteria releasing large amounts of H2S, poisoning the oceans and atmosphere and thinning the ozone layer. These systems then created a cycle of positive feedbacks: more die-offs → more euxinia → more H2S → more die-offs.
Marine ecosystems were forever changed after the extinction. Land ecosystems didn’t recover for ~5 My, and O2 levels remained low throughout much of Triassic time.

Click HERE to see all Mass Extinction Monday posts

itssedimentary:

END-PERMIAN (250 Ma) - “The Great Dying”

Severity: 1st worst

Cause: Eruption of Siberian Traps

Climate: Cold to extremely warm; ocean acidification and anoxia, ozone destruction

Aftermath: Permanent ecosystem reorganization; low O2 for >106 years

There’s good reason why the End-Permian extinction is referred to as “The Great Dying”; 95% of all marine families, 53% of all marine families, 84% of marine genera, and 70% of known land species went extinct,

The extinction likely occurred in three stages:
1. Land extinctions over ~40,000 yrs
2. Very abrupt marine extinctions
3. Second phase of land extinctions

Calcifying marine organisms such as brachiopods and bryozoa were the hardest hit, representative of ocean acidification. The last of the Cambrian fauna also died off, and this was the only known mass extinction of insects

So what exactly made the End-Permian extinction so severe? There truly was a perfect storm to make this the deadliest million years in Earth’s history.

Earth had been emerging from a moderate ice age when the largest flood basalt event in history (the Siberian Traps) occurred, which released vast amounts of CO2. The oceans then became increasingly warm, acidic, stratified, and euxinic from decaying organic matter. The atmosphere also became flooded with light (biogenically fixed) C, possibly from seafloor methane hydrates or from coal gas released as a result of heating from the Siberian Traps. Greenhouse gases soon caused global temperatures to spike, leading to massive extinction. Global euxinia in the oceans then became a severe problem, with sulfate reducing bacteria releasing large amounts of H2S, poisoning the oceans and atmosphere and thinning the ozone layer. These systems then created a cycle of positive feedbacks:
more die-offs → more euxinia more H2→ more die-offs.

Marine ecosystems were forever changed after the extinction. Land ecosystems didn’t recover for ~5 My, and O2 levels remained low throughout much of Triassic time.

Click HERE to see all Mass Extinction Monday posts