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‘Sailing Stones’ in Death Valley

The long version…and no spoilers yet!!

The mystery on the ‘sailing stones’ in Death Valley’s Racetrack playa has been solved and I wrote about a few years ago when it happened, but the video embedded above is so well done, it’s worth revisiting this remote, harsh landscape where large rocks can ‘flow’ uphill. 

SPOILERS (since 2014): On very rare occasions, when it rains in the region, water will accumulate in the playa (discovermagazine.com), and if the temperature dips below freezing a thin layer of ice will cover the playa.  If the wind is powerful and consistent enough, the wind will push the panels of ice against these rocks and over time, the ice floes will push these rocks, leaving behind distinctive trails (latimes.com). This perfect combination of water, wind, ice and heat creates a remarkable signature on the landscape (livescience.com).  The decidedly non-aerodynamic rocks of Death Valley’s Racetrack Playa leave behind a trail in the hot desert.  Numerous attempts using GPS receivers (NatGeo.com) and good ol’ fashioned observations have been made, but observing ice in Death Valley is so rare that it was never observed until 2014 (phys.org). 

Tags: physical, geomorphology, landforms, desert, landscape.

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Pacific nation Tuvalu has grown by 73 hectares over 40 years

“The tiny Pacific nation of Tuvalu – once thought to be under threat from rising sea levels – has grown the size of California’s Disneyland over the past 40 years. It’s mostly thanks to waves dumping extra sediment, sand and gravel on shore lines, according to research by Auckland University scientists. The study, published in the Nature Communications journal on Friday, was the first in-depth look at how much each of Tuvalu’s 101 islands have changed over the decades.”

 

Tags: Oceania, water,  coastal, environment, physical, geomorphology, erosion, geology, landforms.

Source: www.stuff.co.nz

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Alluvial Fans

“When a mountain stream carries a lot of sediment (clay, silt, sand, gravel, cobbles, and boulders) and leaves the confines of the canyon, the sediment is deposited. Over time, this process creates a fan-shaped deposit. The sediment is deposited not because the gradient of the stream decreased, but because the power of the stream dissipates beyond the canyon mouth as the water is spread thin and infiitrates. Many cities are built on alluvium fans, often leading to hazards from flash floods and mudflows.”

Source: www.instagram.com

In mountainous, interior deserts, the largest settlements are usually not deep in the deserts or on top of the mountains but in that in between space.  Many settlements in Central Asia are built on these alluvial fans. 

 

Tags: environment, physical, geomorphology, erosion, geology, California, landforms.

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Corinth Canal

“This photograph, taken by an astronaut aboard the International Space Station, shows the straight line of the Corinth Canal as it crosses a narrow isthmus between mainland Greece (right) and the Peloponnese Peninsula. The canal cuts through the narrowest part of the isthmus of Corinth. The goal was to save ships from the dangerous 700-kilometer voyage around the ragged coastline of the peninsula.”

Source: earthobservatory.nasa.gov

Questions to Ponder: What does the word Isthmus mean and how does this image help tell that story?  When did people start modifying Earth’s physical systems?  What factors do we need to consider when evaluating the impacts of human modifications to the environment?    

 

Tags: water, coastal, landforms, Greece.

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Massive landslide adds to ‘unprecedented’ damage along scenic Highway 1 in Big Sur area

“A massive mudslide along the California coast.  Millions tons of rock/dirt, about 1/3 mile of roadway covered 35-40 feet deep.”

Source: www.latimes.com

A steep slope, unstable ground, and changing moisture content result is this spectacular (and horrifying) example of how the Earth beneath our feet might not be as permanent as we expect it to be.

 

Questions to Ponder: Which type of mass wasting is seen in this particular example?  What conditions would lead to other types of mass wasting?  

 

Tags: physical,  California, geomorphology, erosion, landforms.

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Iceland’s Glacial Melt and Geothermal Activity

Glacial melting and flooding occurs every year by the Skafta River in Iceland. As the water travels down towards the North Atlantic Ocean, incredible patterns are created on the hillsides. Rising lava, steam vents, or newly opened hot springs can all cause this rapid ice melt, leading to a sizable release of water that picks up sediment as it flows down from the glaciers.

 

Tags: geomorphology, physical, Europe, fluvial, water, landforms, images.

Source: www.instagram.com

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A Medieval Abbey Trapped by Tides and Time

“Mont Saint-Michel emerges from the tides in Normandy, France, like an ancient village from a fairytale. The coastal town built on a massive granite rock cuts a dramatic silhouette against the sky, rising from disappearing marshes to a Gothic Abbey at its height. With a permanent population of around 50, this popular tourist destination has a history dating back to at least the Roman era. Fancy a tour before the tides roll in?”

Source: www.youtube.com

Coastal physical geography produces some beautiful landforms such as tombolos.  A tombolo is created when sand deposits attach an island to a larger piece of land–think of it as special type of isthmus.  Mont St. Michel is the world’s most famous example because of the iconic walled city with crowned with a striking medieval abbey.  This is one of those fascinating places for both the human and physical geographer.   

 

Tags: water, physical, coastal, geomorphology, landforms, France, historical, tourism.

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The Whale’s Tail

“The Ballena Marine National Park is located in Puntarenas, at the South Pacific coast of Costa Rica.” 

Source: www.ballenainfocenter.com

This National Park in Costa Rica is a delightful example of many things geographic.  Not only is the local biogeography make this a place famous for whales (ballena in Spanish), but the physical geography also resembles a whale’s tail.  This feature is called a tombolo, where a spit connects an island or rock cluster to the mainland. Additionally, there is also a great community of citizen cartographers mapping out this park and the surrounding communities. 

 

Tags: biogeography, environment, geomorphology, physical, water, landforms.

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Death Valley’s Roving Rocks

Death Valley,California – Giant boulders in the desert look as though their moving all on their own! But could weird weather be behind these roving rocks

Source: www.youtube.com

Since the video above was created, the mystery has been solved.  On very rare occasions, when it rains in the region, water will accumulate in the playa (discovermagazine.com).  If the wind is powerful and consistent enough, the wind will push the panels of ice against these rocks and over time, the ice floes will push these rocks, leaving behind distinctive trails (latimes.com). This perfect combination of water, wind, ice and heat creates a remarkable signature on the landscape (livescience.com).  The video in this article (weather.com) nicely explains how the non-aerodynamic rocks of Death Valley’s Racetrack Playa move, leaving behind their trail in the hot desert.  Numerous attempts using GPS receivers (NatGeo.com) and good ol’ fashioned observations have been made, but observing ice in Death Valley is so rare that no one had ever seen it until now (phys.org).  

 

Tags: physical, geomorphology, landforms, desert, landscape.

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