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Underground Wonders

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More than just a hole in the ground, every cave has its own story. Caves are born in many different fashions, which leave them with different personalities.

Lava Tubes

Lava tube caves are formed when lava flows down the side of a volcano. The lava exposed to the air cools and hardens first, while the lava underneath continues to flow out, leaving an open tube behind when the eruption is finished. The longest and deepest lava tube is 40-mile-long Kazumura Cave on the southeast slope of Mauna Loa in Hawaii.

Tree Molds

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Mount St. Helens has plenty of lava tube caves, and some lava tree molds. The tree molds were formed when an eruption 1,950 years ago knocked down trees and covered them with lava. When the trees burned, the opening left behind would be a perfect mold of the logs.

Sea Caves

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Sea caves are erosional caves, formed by the action of waves against rock, usually along an existing fault. The Blue Grotto of Capri is a popular and photogenic cave due to the appearance of light from the bottom of the cave. Sunlight enters the cave through underwater channels and reflects off the limestone floor.
More types of caves, after the jump.

Wind Caves

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Wind caves are formed by erosion of sandstone by blowing wind. They tend to be pretty shallow and rounded. Gaviota, California is home to some beautifully sculpted wind caves.

Glaciar Caves

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Glaciar caves are also erosional, usually carved by mountain streams flowing into glaciers, but can also be formed by volcanic heat from below. Pictured is a cave carved by water flowing into the Fox Glacier in New Zealand.

Limestone Caves

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Solutional caves are formed when the existing rock is dissolved. The most common type is the limestone cave, because rainwater and groundwater contain acids which dissolve limestone over time. An example is Mammoth Cave system in Kentucky, the world's most extensive cave system at 367 combined miles (and still not completely mapped)!

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Another limestone cave formation, the Sarawak Chamber in the Gunung Mulu National Park in Malaysia is the world's largest single cave chamber, measuring 2,300 feet long, 1,300 feet wide and at least 230 feet high!

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In New Mexico, Lechuguilla Cave and Carlsbad Caverns are a different kind of solutional cave. They were formed by sulphurous acids rising from below. The minerals from the acidic fumes leave amazing and fragile gypsum and sulphur formations such as chandeliers, soda straws, and cave pearls. Although Carlsbad Caverns is a major tourist draw, the more recently-mapped Lechuguilla Cave is off-limits to visitors in order to preserve the environment.

Salt Caves

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Salt caves are also solutional caves, forming and collapsing relatively quickly. The world's longest salt cave (nearly four miles) was discovered just last year on Qeshm Island off the coast of Iran.

For all kinds of information on caves, I recommend a tour of The Virtual Cave.

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science
Tracing Vladimir Nabokov's 1941 Cross-Country Road Trip, One Butterfly at a Time
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Vladimir Nabokov is most famous as a writer, but the Russian scribe was also an amateur—yet surprisingly accomplished—lepidopterist. Nabokov first began collecting butterflies as a child, and after moving to the U.S. in 1940 he began volunteering in the Lepidoptera collections at the American Museum of Natural History.

The following year, the author took a cross-country road trip, driving 4000 miles from Pennsylvania to California. Along the way, he stopped at kitschy roadside motels, which provided atmospheric fodder for his 1955 novel Lolita. Nabokov also collected hundreds of butterfly samples at these rest stops, most of which he ended up donating to the AMNH.

Nabokov would go on to publish multiple scientific papers on lepidoptery—including the definitive scholarly study of the genus Lycaeides, or the “blues”—and produce perhaps thousands of delicate butterfly drawings. Multiple butterfly species were also named after him, including Nabokov’s wood nymph.

In the AMNH’s 360-degree video below, you can trace the author's 1941 cross-country road trip state-by-state, see some of the specimens he collected, and learn how museum curators are using his westward journey to better understand things like species distribution and migration patterns.

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environment
A Coral Reef in Mexico Just Got Its Own Insurance Policy
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The Puerto Morelos coral reef, about 20 miles south of Cancún, is one of Mexico’s most popular snorkeling attractions. It also serves a vital purpose beyond drawing tourists. Like all reefs, it provides a buffer for the coast, protecting nearby beaches from brutal waves and storms. And so the beachside businesses that rely on the reef have decided to protect the coral as they would any other vital asset: with insurance. As Fast Company reports, the reef now has its own insurance policy, the first-ever policy of its kind.

Coral reefs are currently threatened by increasing ocean acidification, warmer waters, pollution, and other ocean changes that put them at risk of extinction. Mass coral bleachings are affecting reefs all over the world. That’s not to mention the risk of damage during extreme storms, which are becoming more frequent due to climate change.

Businesses in Puerto Morelos and Cancún pay the premiums for the Reef & Beach Resilience and Insurance Fund, and if the reef gets damaged, the insurance company will pay to help restore it. It’s not just an altruistic move. By protecting the Puerto Morelos reef, nearby businesses are protecting themselves. According to The Nature Conservancy, which designed the insurance policy, coral reef tourism generates around $36 billion for businesses around the world each year. Perhaps even more importantly to coastal businesses, reefs protect $6 billion worth of built capital (i.e. anything human-made) annually.

When a storm hits, the insurance company will pay out a claim in 10 days, according to Fast Company, providing an immediate influx of cash for urgent repair. (The insurance policy is tied to the event of a storm, not the damage, since it would be hard to immediately quantify the economic damage to a reef.) The corals that break off the reef can be rehabilitated at a nursery and reattached, but they have to be collected immediately. Waiting months for an insurance payout wouldn’t help if all the damaged corals have already floated away.

The insurance policy is one of many new initiatives designed to rehabilitate and protect endangered coastal ecosystems that we now know are vital to buffering the coast from storm surges and strong waves. Coral reefs aren’t the only protective reefs: In the eastern and southern coastal U.S., some restaurants have started donating oyster shells to help rebuild oyster reefs offshore as a storm protection and ecosystem rehabilitation measure.

Considering the outsized role reefs play in coastal protection, more insurance policies may be coming to ecosystems elsewhere in the world. Hopefully.

[h/t Fast Company]

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