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Imaggeo on Mondays: A modern cliff hides ancient dunes

Imaggeo on Mondays: A modern cliff hides ancient dunes

Ancient sand dunes exposed off a cliff face on the shoreline of Nova Scotia at the Islands Provincial Park. The juxtaposition of the high angled strata and flat lying layers above revels the drastic change in climate in Nova Scotia’s history; from vast sand dunes to a calm lake system, and presently the western coastline of the Atlantic Ocean.

Description by Robert Wu, as it first appeared on imaggeo.egu.eu.

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/.

Educators: apply now to take part in the 2019 GIFT workshop!

Educators: apply now to take part in the 2019 GIFT workshop!

The General Assembly is not only for researchers but for teachers and educators with an interest in the geosciences also. Every year the Geosciences Information For Teachers (GIFT) is organised by the EGU Committee on Education to bring first class science closer to primary and high school teachers.

The topic of the 2019 edition of GIFT is ‘Plate tectonics and Earth’s structure – yesterday, today, tomorrow’. This year’s workshop will be taking place on 8–10 April 2018 at the EGU General Assembly in Vienna, Austria.

Teachers from Europe and around the world can apply to participate in the 2019 edition of GIFT, and to receive a travel and accommodation stipend to attend the workshop, by November 12. Application information is available for download in PDF format, a document which also includes the preliminary programme of the workshop.

Not sure what to expect? More information about GIFT workshops can be found in the GIFT section of the EGU website. You can also take a look at a blog post about the 2015 workshop and also learn what the workshop is like from a teacher’s perspective here. You might also find videos of the 2018 workshop useful too.

Imaggeo on Mondays: Life between the arid mountains of Gansu, China

Imaggeo on Mondays: Life between the arid mountains of Gansu, China

Even within Earth’s more arid environments, you can find life!

This featured photo was taken near the Lanzhou Zhongchuan Airport, about 50 km away from Lanzhou city, the capital of Gansu province in Western China. The area lies in a region between the Qinghai-Tibet Plateau and the Loess Plateau, with an elevation ranging from 1,500 m to 2,200 m. The landscape is dominated by a network of ridges and valleys; the Loess Plateau in particular is known for its highly erodible soil.

The region is a typical temperate or semi-arid area receiving just 260-290 mm of precipitation annually with a potential evapotranspiration of about 1660 mm each year, according to the Gaolan and Yongdeng National Meteorological Stations. However, even in these dry conditions, you can still find pockets of agricultural plots nestled between the winding mountain ridges. Farmers in this region commonly rely on an agricultural method called terrace farming, where crops are grown on graduated platforms, resembling wide steps. Often used in dry mountainous environments, the practice not only creates a flat surface for farming, but also reduces soil erosion and efficiently conserves water. The terraced farms in this area are mainly distributed in the valley where lands are irrigated for wheat and maize production.

By Olivia Trani, Communications Officer, and Xiaoming Wang, State Key Laboratory of Cryospheric Science, Chinese Academy of Science, Lanzhou, China

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: How erosion creates natural clay walls

Imaggeo on Mondays: How erosion creates natural clay walls

The badlands valley of Civita di Bagnoregio is a hidden natural gem in the province of Viterbo, Italy, just 100 kilometres from Rome. Pictured here is the ‘wall,’ one of the valley’s most peculiar features, where you can even find the wooden structural remains of a trail used for agricultural purposes in the 19th and 20th centuries.

The photograph was taken by Chiara Arrighi, a post-doc research assistant at the University of Florence (Italy), in May last year after climbing roughly 200 metres from the bottom of the Chiaro creek valley. Trails in this region are not well traced or maintained, so she had to find her own way up among the chestnut woods. Once at the top, the trail becomes narrow and unprotected. “The inhabitants of the area still do not exploit this natural beauty as a tourist attraction,” said Arrighi. “In fact, nobody was on the trail, and the silence [was] unreal.”

Badlands are a typical geological formation, where grains of sand, silt and clay are clumped together with sedimentary rock to form layers, which are then weathered down by wind and water. The terrain is characterised by erosive valleys with steep slopes, without vegetation, separated by thin ridges.

Due to the slope’s steep angle and the clay’s low permeability, little water is able enter the soil. Instead water quickly flows across the surface, removing surface clay and carving into the slopes as it does so.

The morphological evolution of the clay slopes can be very rapid (for example, rock falls can occur quite suddenly after heavy rainfall) and occurs as a result of several physical mechanisms, such as mud flows, solifluction (slow movement of wet soil towards the bottom of the valley) and sliding.

During the evolution of the badlands, peripheral portions of the terrain made up of volcanic deposits (tuff cliffs) rose up from the landscape, bordered by nearly vertical slopes (called scarps). Many towns have been built on these erected hilltops, such as Civita di Bagnoregio.

By Chiara Arrighi and Olivia Trani

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/.