GeoLog

geomorphology

Imaggeo on Mondays: The Henry Mountains, living textbook of modern geomorphology

Imaggeo on Mondays: The Henry Mountains, living textbook of modern geomorphology

In 1877, the United States Geological Survey published a report “On the Geology of the Henry Mountains”, on the small range of peaks in southern Utah, pictured here. Up to that point, little scientific study had been made of the unassuming peaks, but the author of the report, one Grove Karl Gilbert, not only detailed the structure and mineralogy of the landscape, but in doing so also laid the foundations for much of modern geomorphology.

While beautiful, the range is isolated and of limited economic value; Gilbert himself notably wrote that “No one but a geologist will ever profitably seek out the Henry Mountains”, while the name given to the range by the Navajo Nation is Dził Bizhiʼ Ádiní, literally meaning “mountain whose name is missing”. And yet, the wildness of the range is sufficient attraction for some!

by Robert Emberson

Robert Emberson is a Postdoctoral Fellow at NASA Goddard Space Flight Center, and a science writer when possible. He can be contacted either on Twitter (@RobertEmberson) or via his website (www.robertemberson.com)

Imaggeo is the EGU’s online open access geosciences image repository. All geoscientists (and others) can submit their photographs and videos to this repository and, since it is open access, these images can be used for free by scientists for their presentations or publications, by educators and the general public, and some images can even be used freely for commercial purposes. Photographers also retain full rights of use, as Imaggeo images are licensed and distributed by the EGU under a Creative Commons licence. Submit your photos at http://imaggeo.egu.eu/upload/.

Imaggeo on Mondays: Fairy chimneys in Love Valley

Imaggeo on Mondays: Fairy chimneys in Love Valley

Every year tourists from around the world flock to Love Valley in Göreme National Park in the Cappadocia region of central Turkey to marvel at the region’s peculiarly pointy geological features. These cone-shaped formations, known as ‘fairy chimneys’ or hoodoos, dominate the park’s skyline, with some rocky spires extending up to 40 metres towards the sky.

While the name ‘fairy chimney’ suggests mythical origins, these rocks began to take shape millions of years ago, when many active volcanoes dominated the region. “The deposits of [volcanic] ash, lava and basalt laid the foundations for today’s landscape,’ commented Alessandro Demarchi in the photo’s description, who captured the stunning photograph featured today. The volcanic material consolidated into a soft rock known as ‘tuff.’ Then over the years, natural weathering forces like wind and water eroded weaker parts of the rock away, leaving behind the pinnacles we see now.

Around the 4th century, during the reign of the Roman empire, many Christian pilgrims traveled to Cappodocia to flee persecution. They built their new life into the region’s rocks, carving out a network of homes and churches from the towers of tuff. If you look closely at background of the image, you can even spot remnants of their handiwork.

The region was named a UNESCO World Heritage Site in 1985, and today you can enjoy the extraordinary geological formations, as well as their cultural history, either from the ground or up in the air through hot air balloon tours.

Imaggeo is the EGU’s online open access geosciences image repository. All geoscientists (and others) can submit their photographs and videos to this repository and, since it is open access, these images can be used for free by scientists for their presentations or publications, by educators and the general public, and some images can even be used freely for commercial purposes. Photographers also retain full rights of use, as Imaggeo images are licensed and distributed by the EGU under a Creative Commons licence. Submit your photos at http://imaggeo.egu.eu/upload/.

Imaggeo on Mondays: The Gower Peninsula, a coast marked by time

Imaggeo on Mondays: The Gower Peninsula, a coast marked by time

The Gower Peninsula in South Wales, United Kingdom, is a spectacular site to view a sunset. However, to geologists, the shore is also a prime spot to find artifacts from Earth’s ancient and recent past.

“The limestone coastline is dotted with caves that are rich in Quaternary flora and fauna,” said Mike Smith a visiting researcher at Plymouth University (UK) and photographer of this featured image. “Including the famous Red Lady of Paviland, the oldest known ceremonial burial in Western Europe, at 30,000 years before present.”

The peninsula is also known for its “dramatic and visible evidence of climate change over a range of temporal scales,” according to Smith.

A solifluction terrace on the Rhossili Bay in the Gower Peninsula.
Credit: Stephen Codrington. Planet Geography 3rd Edition, 2005 (distributed via Wikimedia Commons).

For example, at the peak of Earth’s most recent glacial period, when the northern ice sheets had made their greatest advances southward, the Gower Peninsula was one of the southern most regions overcome by ice.

Though the last glacial period ended more than 11,00 years ago, you can find evidence of this tundra environment today, if you know what to look for.

For instance, much of the Peninsula’s coastlines are lined by small steeply sloping ridges, separating the coast’s green hillslopes from its sandy beaches. These structures are often referred to as solifluction terraces, and are formed when frozen ground thaws, causing soil, rock and other debris to move downslope.

Additionally, the Gower Peninsula is also host to remnants of our very recent history.

Pictured above are the remains of the shipwrecked Helvetica, a cargo vessel from the late 19th century that had been transporting 500 tons of timber before meeting its untimely end on the banks of Worm’s Head, a small rocky island just a few kilometres long, visible from the peninsula’s shores.

On 1 November, 1887, strong gales just off the coast had taken a hold of the ship, leaving it unable to dock at Swansea Harbour. Instead, the forceful winds blew the vessel into the sandbank of Helwick Sands and then dragged the ship to its final resting place, the shores of Worm’s Head. Helvetica’s captain and crew were forced to abandon ship, and after its cargo was relocated and salvageable parts stripped away, the ship settled deep into the sand.

“The Helvetica is now permanently buried in the beach on a coastline that is bordered by extensive sand dune systems,” remarks Smith.  With each year since, the Atlantic has reclaimed more of the ship, and now just the bare bones of the wreckage remain.

References

Helvetica (Explore Gower)

Hall, Adrian. Cairngorm Landscapes [Edinburgh, Scotland], Solifluction, 2002

Imaggeo on Mondays: Refuge in a cloudscape

Imaggeo on Mondays: Refuge in a cloudscape

The action of glaciers combined with the structure of the rock to form this little platform, probably once a small lake enclosed between a moraine at the mountain side and the ice in the valley.

Now it has become a green haven in the mountain landscape, a perfect place for an alp. In the Alps, stratus clouds opening up on autumn mornings often create gorgeous light display.

That day, some of the first light landed on this exact spot, while the mountain shadows still covered the valley bottom.

Description by Julien Seguinot, as it first appeared on imaggeo.egu.eu

Imaggeo is the EGU’s online open access geosciences image repository. All geoscientists (and others) can submittheir photographs and videos to this repository and, since it is open access, these images can be used for free by scientists for their presentations or publications, by educators and the general public, and some images can even be used freely for commercial purposes. Photographers also retain full rights of use, as Imaggeo images are licensed and distributed by the EGU under a Creative Commons licence. Submit your photos at http://imaggeo.egu.eu/upload/.