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Imaggeo on Mondays: Emerald Moss

Imaggeo on Mondays: Emerald Moss

The high peaks of the Tien Shan Range, one of the biggest and largest mountain ranges of Central Asia, conjure up images of snowcapped peaks, rugged terrains and inhospitable conditions. Yet, if you are prepared to look a little further, the foothills of these towering peaks are a safe haven for life. Bulat Zubairov, a researcher at Humboldt University, takes us on a journey of discovery to the Ile-Alatau National Park in today’s Imaggeo on Mondays post.

This photo was taken in the Ile-Alatau National Park, approximately at this point: 43° 9’31.81″N, 77° 5’47.36″E. The National Park is located on the northern slopes of Ile Alatau (Zailiysky Alatau) mountain range, which is a part of the Tien Shan Range and it is a main recreation zone for people who live in Almaty (the biggest city in Kazakhstan).

The photo was taken in a small watershed – an area or ridge of land which separates two bodies of water – where a small river flows. The upstream section of the watershed dries up periodically over the summer periods.

Reflecting the rich fauna and flora of the Ile-Alatau National Park, more than 100 species of mosses can be found in this area in a wooded zone. They play a significant role in regulation of water balance of the region, preventing soil erosion, supporting special types of biocenosis and promoting biodiversity conservation. Being one of the indicators of ecosystem condition, mosses also play a key role in monitoring and assessment of current changes in ecology of the region, especially taking into account ever-growing anthropogenic pressures. All this shows the relevance of efforts aimed at researching of such a beautiful and such important part of nature as mosses.

By Bulat Zubairov, PhD student at Humboldt University in Berlin

If you pre-register for the 2016 General Assembly (Vienna, 17 – 22 April), you can take part in our annual photo competition! From 1 February up until 1 March, every participant pre-registered for the General Assembly can submit up three original photos and one moving image related to the Earth, planetary, and space sciences in competition for free registration to next year’s General Assembly!  These can include fantastic field photos, a stunning shot of your favourite thin section, what you’ve captured out on holiday or under the electron microscope – if it’s geoscientific, it fits the bill. Find out more about how to take part at http://imaggeo.egu.eu/photo-contest/information/.

 

EGU Photo Contest 2016

EGU Photo Contest 2016

If you are pre-registered for the 2016 General Assembly (Vienna, 17 – 22 April), you can take part in our annual photo competition! Winners receive a free registration to next year’s General Assembly!

The seventh annual EGU photo competition opens on 1 February. Up until 1 March, every participant pre-registered for the General Assembly can submit up three original photos and one moving image on any broad theme related to the Earth, planetary, and space sciences. Shortlisted photos will be exhibited at the conference, together with the winning moving image, which will be selected by a panel of judges. General Assembly participants can vote for their favourite photos and the winning images will be announced on the last day of the meeting.

We particularly encourage submissions representing Active Planet, as there will be an additional prize for the photo that best captures the theme of the conference.

If you submit your images to the photo competition, they will also be included in the EGU’s open access photo database, Imaggeo. You retain full rights of use for any photos submitted to the database as they are licensed and distributed by EGU under a Creative Commons license.

You will need to register on Imaggeo so that the organisers can appropriately process your photos. For more information, please check the EGU Photo Contest page on Imaggeo.

Previous winning photographs can be seen on the 20102011, 2012,  2013, 2014 and 2015 winners’ pages.

In the meantime, get shooting!

Imaggeo on Mondays: A hidden waterfall

Imaggeo on Mondays: A hidden waterfall

It’s fascinating how a relatively small outcrop, carved out by rivers and ancient ice, can reveal much about the geological history of an area. Today’s Imaggeo on Mondays post is one such example. Antonio Girona, a researcher at the University of Zaragoza, gives us a whirlwind tour of the geological history of the rocks revealed by the Sorrosal Waterfall, in Spain.

The visit to the Sorrosal Waterfall is an obligatory stop in your way to the Ordesa National Park, located in the Aragonese Pyrenees (NE-Spain). In the northern area of Huesca province, after a short walk from the town of Broto, this hidden waterfall can be found showing the geomorphological and geological history of the valley.

The Sorrosal Waterfall is located in the confluence of two valleys: Broto Valley, run by the Ara River (nowadays the longest river in the Pyrenees with 67 km) and Sorrosal Valley, a hanging valley 125 m above the position from which this photograph was taken. This waterfall was generated by the combined action of a glacier and the river. During the Ice Age, this site was covered by a 30 km long, 370 m deep glacier that shaped the valley that we nowadays call Broto Valley. At the same time Sorrosal river, fed by a small glacier in its headwaters, carved this valley transversely resulting in the Sorrosal Waterfall.

As a consequence of the slope between the two valleys, an interesting outcrop of geological interest can be observed. The rocks were originated from deep-marine sediments (turbidites) from the Eocene, which suffered a series of stepping folds as a result of the Pyrenees Alpine orogeny, becoming the wavy structure than can be appreciated nowadays.

 

By Antonio Girona Garcia, University of Zaragoza.

 

If you pre-register for the 2016 General Assembly (Vienna, 17 – 22 April), you can take part in our annual photo competition! From 1 February up until 1 March, every participant pre-registered for the General Assembly can submit up three original photos and one moving image related to the Earth, planetary, and space sciences in competition for free registration to next year’s General Assembly!  These can include fantastic field photos, a stunning shot of your favourite thin section, what you’ve captured out on holiday or under the electron microscope – if it’s geoscientific, it fits the bill. Find out more about how to take part at http://imaggeo.egu.eu/photo-contest/information/.

 

 

Geosciences Column: Three hundred years probing the deep seas

Patagonia Blues, Credit: Agathe Lisé-Pronovost (distributed via imaggeo.egu.eu)

Patagonia Blues, Credit: Agathe Lisé-Pronovost (distributed via imaggeo.egu.eu)

The depths of the deep blue have fascinated explorers, scientists and humanity for centuries. And is it any wonder? 71% of the Earth’s surface is covered by oceans teaming with riches, from unique forms of life to precious metals.Even today, there are vast regions of the ocean floors that remain unexplored and of which we know very little about. Some might argue the oceans are the last unexplored frontier on the planet.

To quote Steinar Ellefmo, an Associate Professor at NTNU’s Department of Geology and Mineral Resources Engineering, “We actually know more about the moon than the seafloor.”

The divisions of the worlds oceans. Attribution: K. Aainsqatsi, distributed via Wikipedia.org

The divisions of the worlds oceans. Attribution: K. Aainsqatsi, distributed via Wikipedia.org. Click to enlarge.

The oceans are divided into zones according to depth, temperature and how much light those depths receive. The cold and dark waters of the twilight zone and beyond continue to be the focus of much attention and fascination today. But the pursuit of understanding the ocean deep is not new; it dates back at least 400 years, if not longer.

Reconstructing the historical records of the origins of the exploration of the ocean depths is not always easy. Hampered by incomplete recording of data, poor cross referencing between studies and limited value attributed to the findings made by non-scientific sea endeavours such as fishing, historical accounts can be piecemeal. A recent paper, published in the open access journal Biogeosciences, aims to address some of these inconsistencies, as well as setting the record straight on an age-old historical misrepresentation.

How deep are the oceans and seas?

The first scientific records of attempts to measure ocean depth in the bathyal zone (defined by Gage and Tyler as depths below 200m), date back to 1521: Magellan, a Portuguese explorer who organised the first Spanish expedition to the East Indies, unsuccessfully tried to sound the ocean bottom between two pacific coral islands. It wasn’t until the 18th century that the quest for understanding the ocean floor took off in earnest.

Expedition records show that a number of 18th century explorers were, allegedly, able to sound ocean depths up to 1950m (the John Ross expedition to the Northwest Passage of the Arctic). We now know that the depths of those soundings are around half that of the depths published and likely never exceeded 1100m.

An encounter between British Royal Navy expedition, led by John Ross, and Inuit people on Baffin Bay, Greenland. The artist John Sacheuse (sometimes spelled Sackhouse) was an Inuit who acted as interpreter for Ross’s party.

An encounter between British Royal Navy expedition, led by John Ross, and Inuit people on Baffin Bay, Greenland. The artist John Sacheuse (sometimes spelled Sackhouse) was an Inuit who acted as interpreter for Ross’s party.

The problem arose from the technique employed: a line and plummet was allowed to sink to the ocean bottom and the final length of the line recorded, but divergences between the apparent and true depths plagued measurements throughout the 18th and 19th centuries. For instance, The James Clark Ross expedition (1839 -1843), sounded the ocean depth east of Brazil at 8400m, but these depths are never encounter in the region. It wasn’t until dredging became possible, and common, place that depth measurements and sampling of the sea bed saw an improvement.

Life in the bathyal zone and beyond

The aims of taking measurements of the depth of the oceans were twofold: early explorers not only wanted to know how far down our oceans extend, but also whether the waters beyond where light can penetrate could sustain life.

French naturalist François Péron proposed that the sea beds were covered by eternal ice and so the deep waters of the oceans would be unable to sustain life. On theoretical grounds, British geologist Henry de la Beche, agreed with Péron’s concept of lifeless deep ocean waters. But it was the work of naturalist Edward Forbes during the mid-1800s which really cemented the notion of an azoic layer in the oceans. While involved in sea-dredging expeditions around The British Isles and the Aegean Sea, Forbes noticed that life became increasingly sparse with greater water depth and developed the theory that ocean waters were devoid of life at depths in excess of 550m.

Basket star - Gorgonocephalus arcticus (Leach, 1819) (from Koehler 1909, pl. 9; as Gorgonocephalus agassizi; Stimpson, 1854). This is the species that was caught during the John Ross expedition.

Basket star – Gorgonocephalus arcticus (Leach, 1819) (from Koehler 1909, pl. 9; as Gorgonocephalus agassizi; Stimpson, 1854). This is the species that was caught during the John Ross expedition. From Etter and Hess, 2015. Click to enlarge.

Contrary to popular belief, the earliest recovery of deep water life was not that of the famous basket star – a branched arm, sometimes medusa-like, sea star – by John Ross in 1818. The first published record is significantly older. Specimens of upper bathyal stalked crinoid (Cenocrinus asterius) were brought up by fishing lines in the Caribbean, with specimens reaching Europe in 1761 and 1762. However, the depths at which they had been recovered were never recorded. Deep-sea fish were also recovered from the Azores, Madeira, northern Spain, Sicily and Antillean islands, but often found in shallow waters or as dead specimens floating near shore.

Cenocrinus asterius (Linné, 1767) (from Guettard, 1761, pl. 8; as “Palmier marin”). This was the first modern stalked crinoid that was described.

Cenocrinus asterius (Linné, 1767) (from Guettard, 1761, pl. 8; as “Palmier marin”). This was the first modern stalked crinoid that was described.  From Etter and Hess, 2015. Click to enlarge.

The peculiar appearance, especially in the case of the stalked crinoids, and lack of detailed records as to what depths they’d been recovered from, meant that studies of these specimens focused on their potential to be ‘living fossils’, rather than geographical distribution within the water column. Even John Ross’, now famous, basket star was neglected from much of the early 19th century literature. Not only that, the issues with accurately ascertaining the depths of soundings and the belief that organisms became entangled higher up in the water column, recovery of specimens via this method was considered far less reliable than dredging.

Had the records of earlier soundings been accurately logged and all discoveries portrayed in the literature of the time, would Forbes’ theory of a lifeless deep ocean been debunked sooner? As well as correcting the long established notion that John Ross’ basket star was the first record of deep water life, the findings of the Biogeosciences review paper highlight the importance of not uncritically following previously published synthesis of historical literature.

 

By Laura Roberts Artal, EGU Communications Officer.

 

References

Etter, W. and Hess, H.: Reviews and syntheses: the first records of deep-sea fauna – a correction and discussion, Biogeosciences, 12, 6453-6462, doi:10.5194/bg-12-6453-2015, 2015.

Gage, J. D. and Tyler, P. A.: Deep-Sea Biology: a Natural History of Organisms at the Deep-Sea Floor, Cambridge University Press, Cambridge, UK, 504 pp., 1991.

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