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Imaggeo on Mondays: The Crossroads of Flood and Drought

Imaggeo on Mondays: The Crossroads of Flood and Drought

This picture was taken on the way back from collecting field measurements at the Lordsburg Playa in southwestern New Mexico, USA. The setting sun highlights the contrast between the dry, cracked soil and the standing water from antecedent rainfall.

A playa is a flat topographic depression in arid or semi-arid regions that contains a large amount of deposited sediment. When the surface of the playa is dry, this deposited sediment is exposed and at risk of being entrained into the atmosphere by wind.

With an extent of approximately 250 square kilometers, Lordsburg Playa is a dust ‘hot spot’ in the southwestern Unites States. Dust events originating from the playa are normally small, but they can contain high dust concentrations and occur frequently during the dry season in spring.

The Lordsburg Playa is of particular interest to the local population, as the interstate highway I-10 crosses over the region. Under windy conditions, dust emissions from the playa can drastically reduce visibility on the highway and cause severe traffic accidents.

In October 2016, I went on a one-week field trip to the playa, installing a temporary measurement site to study local dust emission mechanisms. At that time, parts of the playa were still flooded from summer monsoon precipitation. During the field trip, we observed a local, but strong dust event. The event started in the morning and peaked at around 9:00 am when visibility was reduced to a few meters for a short time. Fortunately, the dust was blown northward during this event and the highway was not affected. Visibility recovered shortly after, but small-scale dust phenomena such as dust plumes and dust devils occurred almost continuously during most of the day.

By Martina Klose, a post-doctoral researcher at the Barcelona Supercomputing Center (BSC) in Spain

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 best of imaggeo in 2017

Imaggeo on Mondays: The best of imaggeo in 2017

Imaggeo, our open access image repository, is packed with beautiful images showcasing the best of the Earth, space and planetary sciences. Throughout the year we use the photographs submitted to the repository to illustrate our social media and blog posts.

For the past few years we’ve celebrated the end of the year by rounding-up some of the best Imaggeo images. But it’s no easy task to pick which of the featured images are the best! Instead, we turned the job over to you!  We compiled a Facebook album which included all the images we’ve used  as header images across our social media channels and on Imaggeo on Mondays blog post in 2017 an asked you to vote for your favourites.

Today’s blog post rounds-up the best 12 images of Imaggeo in 2017, as chosen by you, our readers.

Of course, these are only a few of the very special images we highlighted in 2017, but take a look at our image repository, Imaggeo, for many other spectacular geo-themed pictures, including the winning images of the 2017 Photo Contest. The competition will be running again this year, so if you’ve got a flare for photography or have managed to capture a unique field work moment, consider uploading your images to Imaggeo and entering the 2018 Photo Contest.

Alpine massifs above low level haze . Credit: Hans Volkert (distributed via imaggeo.egu.eu).

The forward scattering of sunlight, which is caused by a large number of aerosol particles (moist haze) in Alpine valleys, gives the mountain massifs a rather plastic appearance. The hazy area in the foreground lies above the Koenigsee lake; behind it the Watzmann, Hochkalter, Loferer Steinberge and Wilder Kaiser massifs loom up behind one other to the right of the centre line. Behind them is the wide Inn valley, which extends right across the picture.

A lava layer cake flowing . Credit: Timothée Duguet (distributed via imaggeo.egu.eu)

Check out a post from back in May to discover how layers of alternating black lavas and red soils built up to form a giant ‘mille feuilles’ cake at Hengifoss, Iceland’s third-highest waterfall.

Sediment makes the colour . Credit: Eva P.S. Eibl (distributed via imaggeo.egu.eu)

Earth is spectacularly beautiful, especially when seen from a bird’s eye view. This image, of a sweeping pattern made by a river in Iceland is testimony to it. Follow the link to learn more about river Leirá which drains sediment-loaded glacial water from the Myrdalsjökull glacier in Iceland.

Movement of ancient sand . Credit: Elizaveta Kovaleva (distributed via imaggeo.egu.eu).

Snippets of our planet’s ancient past are frozen in rocks around the world. By studying the information locked in formations across the globe, geoscientist unpick the history of Earth. The layers in one of the winning images of the 2017 photo contest may seem abstract to the untrained eye, but Elizaveta Kovaleva (a researcher at the University of the Free State in South Africa) describes how they reveal the secrets of ancient winds and past deserts in a blog post we published in November.

View of the Tuva River and central mountain range
. Credit: Lisa-Marie Shillito (distributed via imaggeo.egu.eu).

Initially, this photo may seem like any other tropical paradise: lush forests line a meandering river, but there is much more to the forests in the foreground than first meets the eye.

On the way back from Antarctica. Credit: Baptiste Gombert (distributed via imaggeo.egu.eu).

Our December 2017 header image – On the way back from Antarctica, by Baptiste Gombert – celebrated #AntarcticaDay.

Angular unconformity. Credit: André Cortesão (distributed via imaggeo.egu.eu).

It is not unusual to observe abrupt contacts between two, seemingly, contiguous rock layers, such as the one seen above. This type of contact is called an unconformity and marks two very distinct times periods, where the rocks formed under very different conditions.

Find a new way . Credit: Stefan Winkler (distributed via imaggeo.egu.eu)

Stephan Winkler’s 2017 Imaggeo Photo Contest finalist photo showcases an unusual weather phenomenon…find out more about this process in the post from last year.

On the way back from Antarctica. Credit: Alicia Correa Barahona (distributed via imaggeo.egu.eu).

August’s social media header image showcases how, in the altiplano of Bolivia, Andean ecosystems, life and the hydrological cycle come together.

Icelandic valley created during a volcanic eruption. Credit: Manuel Queisser (distributed via imaggeo.egu.eu).

The image shows a valley in the highland of Iceland carved out during a volcanic eruption with lava coming from the area visible in the upper right corner. The landscape is playing with the viewers sense of relation as there is no reference. The valley is approximately 1 km wide. The lower cascade of the water fall is ca. 30 m high. A person (ca. 3 pixels wide) is located near the base of the water fall about 50 m away. It was our October header image.

Despite being one of the driest regions on Earth, the Atacama desert is no stranger to catastrophic flood events. This post highlights how the sands, clays and muds left behind once the flood waters recede can hold the key to understanding this natural hazard.

The heart of the Canadian Rocky Mountains. Credit: Jennifer Ziesch (distributed via imaggeo.egu.eu).

“I saw one of the most beautiful place on earth: The glacially-fed Moraine Lake in the Banff National Park, Canada. The lake is situated in the Valley of the Ten Peaks. The beautiful blue colour is due to the mix of glacier water and rock flour,” says Jennifer, who took the photograph of this tranquil setting.

Symbiosis of fire, ice and water . Credit: Michael Grund (distributed via imaggeo.egu.eu)

This mesmerising photograph is another of the fabulous finalists (and winner) of the 2017 imaggeo photo contest. The picture, which you can learn more about in this blog post, was taken at Storforsen, an impressive rapid in the Pite River in northern Sweden, located close to the site of a temporary seismological recording station which is part of the international ScanArray project. The project focuses on mapping the crustal and mantle structure below Scandinavia using a dense temporary deployment of broadband seismometers.

f you pre-register for the 2018 General Assembly (Vienna, 08 – 13 April), you can take part in our annual photo competition! From 15 January up until 15 February, 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/.

MinCup: Elevating humble minerals to new heights

MinCup: Elevating humble minerals to new heights

Throughout October and November, the world of (Earth science) Twitter was taken by storm: Day after day, Eddie Dempsey (a lecturer at the University of Hull, and @Tectonictweets for those of you more familair with his Twitter handle) pitted minerals against each other, in a knock out style popular contest. The aim? To see which mineral would eventually be crowned the best of 2017.

Who knew fiery (but good natured) rows could explode among colleagues who felt, strongly, that magnetite is far superior to quartz or plagioclase? The Mineral Cup hashtag (#MinCup) was trending, it was in everyone’s mouth. Who would you vote for today?

What started as a little fun, became a true example of great science communication and how to bring a community of researchers, scattered across the globe, together.

And then Hazel Gibson (former EGU Press Assistant, @iamhazelgibson) came along. She was an active participant in the competition, but also contributed beautiful sketches of every mineral featured, and shared them for all to see by tagging them with the #MinCup hashtag. We all know that a picture is worth more than a thousand words, so when Hazel’s hand drawn sketches where paired with an already rocking contest, it’s impact and reach was truly cemented.

Between them, Eddie and Hazel had managed to elevate the humble mineral to new heights.

Why do minerals matter?

Minerals are hugely underrated. They are often upstaged by the heavy-weights of the geosciences: volcanoes, earthquakes, hurricanes, fossils and melting glaciers (to name but a few).

But they shouldn’t be.

Minerals are the building blocks of all rocks, which in turn, are the foundation of all geology.

Whether you study the processes which govern how rivers form, or ancient magnetic fields, or fossils, chances are your work will, at some stage, involve looking at, studying, or at the very least understanding (some) minerals. Mineralogy 101 (or whatever it’s precise name was at your university) is a rite of passage for any aspiring Earth scientist. I still remember hours spent painstakingly looking down a microscope, drawing and annotating sketches trying to decipher the secrets of the Earth’s ancient past, locked in minerals.

And that’s just the beginning.

Minerals are of huge economic and, therefore societal importance, too. Many minerals are vital ingredients in house-hold products and contribute to the manufacturing processes of many others. Yet, they fail to make headlines and their true significance, often, goes unnoticed.

So, in hopes to further highlight the relevance and importance of minerals, I’ve picked a few of the #MinCup minerals and explained why they (should) matter (to you).

Gypsum

Gypsum will form in lagoons, where ocean waters are high in calcium and sulfate content, and where the water evaporates slowly overtime. In rocks, it is associated with sedimentary beds which can be mined to extract the mineral, but it can also be produced by evaporating water with the right chemical composition.

Gypsum has been used in construction and decoration (in the form of alabaster) since 9000 B.C.  Today, it has a wide variety of common uses. Did you know that many fruit juice companies use gypsum to aid the extraction of the liquid? It is also used in bread and dough mixes as a raising agent. And it’s uses aren’t limited to just the food and drink industry. It is also commonly used as a modelling material for tooth restorations and helps keeps us safe when added to plastic products where it acts as a fire retardant.

Magnetite

Geologically speaking, magnetite holds the clues to understand the Earth’s ancient magnetic field. Credit: Hazel Gibson

Typically, greyish black or black, magnetite is an important iron ore mineral. It occurs in many igneous and volcanic rocks and is the most magnetic of all minerals. For it to form, magma has to cool, slowly, so that the minerals can form and settle out of the magma.

Due to its magnetic nature, it has fascinated human-kind for centuries: it paved the way for the invention of the modern compass.  The iron content in magnetite is higher than its more common cousin haematite, making it very sought after. Iron ore is the source of steel, which is used universally throughout modern infrastructure.

Geologically speaking, magnetite holds the clues to understand the Earth’s ancient magnetic field. As magnetite-bearing rocks form, the magnetite within them aligns with the Earth’s magnetic field. Since this rock magnetism does not change after the rock forms, it provides a record of what the Earth’s magnetic field was like at the time the rock formed.

Diamond

Arguably, one of the most well-known of the minerals, diamond is unique, not only for its beauty and the high prices it reaches, but also for its properties. Not only is it the hardest known mineral, it is also a great conductor of heat and has the highest refractive index of any mineral.

Though mostly sought after by the jewellery industry, only 20% of all diamonds are suitable for use as a gem. Due to it’s hardness, diamond is mined for use in industrial processes, to be used as an abrasive and in diamond tipped saws and drills. Its optical properties mean it is used in electronics and optics; while it’s conductive properties mean it is often used as an insulator too.

Diamond: perhaps the most sought after mineral of them all? Credit: Hazel Gibson

Olivine

Last, but absolutely not least, let’s talk about Olivine – the winner of #MinCup 2017.

Olivine is a pretty, commonly green mineral. Because it forms at very high temperatures, it is one of the first minerals to take shape as magma cools, and given enough time, can form specimens which are easily seen with the naked eye. Changes in the behaviour of seismic waves as they traverse the Earth indicate that Olivine is an important component of the Earth’s inner layer – the Mantle.

It’s a relatively hard mineral, but overall hasn’t got highly sought-after properties and, as result, has been used rather sparingly in industrial processes. In the past it has been used in blast furnaces to remove impurities from steel and to form a slag, as well as a refractory material, but both those uses are in decline as cheaper materials come to the market.

Perhaps better known is its gemstone counterpart: peridot, a magnesium rich form of Olivine. It has been coveted for centuries, with some arguing that Cleopatra’s famous ‘emeralds’, where in fact peridote. Until the mid-90s the US was the major exporter of the gem stones, but deposits in Pakistan and China now challenge the claim.

So, do you think Olivine was the rightful winner of #MinCup 2017? With a new edition of the popular contest set to return in 2018, perhaps it’s time to shout about the properties and uses of your favourite mineral from the roof tops? Not only might it ensure it is crowned winner next year, but you’ll also be contributing to making the value of minerals known to the wider public. Heck! If you’d like to tell us all about the mineral you think should be the next champion, why not submit a guest post to GeoLog?

In the meantime, if you haven’t already got your hands on one, Hazel tells me there are a few of her charity #MinCup 2017 calendars up for grabs, so make sure to secure your copy – and contribute to a good cause at the same time.

By Laura Roberts Artal, EGU Communications Officer

August GeoRoundUp: the best of the Earth sciences from around the web

August GeoRoundUp: the best of the Earth sciences from around the web

Drawing inspiration from popular stories on our social media channels, as well as unique and quirky research news, this monthly column aims to bring you the best of the Earth and planetary sciences from around the web.

Major Stories

On August 25th Hurricane Harvey made landfall along the southern coast of the U.S.A, bringing record breaking rainfall, widespread flooding and a natural disaster on a scale not seen in the country for a long time. In fact, it’s the first time since 2005 a major hurricane has threatened mainland U.S.A. – a record long period.

But Harvey’s story began long before it brought destruction to Texas and Louisiana.

On August 17th,the National Space Agency (NASA) satellite’s first spotted a tropical depression forming off the coast of the Lesser Antilles. From there the storm moved into the eastern Caribbean and was upgraded to Tropical Storm Harvey where it already started dropping very heavy rainfall. By August 21st, it had fragmented into disorganised thunderstorms and was spotted near Honduras, where heavy local rainfall and gusty winds were predicted.

Over the next few days the remnants of the storm travelled westwards towards Nicaragua, Honduras, Belize and the Yucatan Peninsula. Forecasters predicted that, owing to warm waters of the Gulf of Mexico and favorable vertical wind shear, there was a high chance the system could reform once it moved into the Bay of Campeche (in the southern area of the Gulf of Mexico) on August 23rd. By August 24th data acquired with NASA satellites showed Harvey had began to intensify and reorganise. Heavy rainfall was found in the system.

Harvey continued to strengthen as it traveled across the Gulf of Mexico and weather warnings were issued for the central coast of Texas. Citizens were told to expect life-threatening storm surges and freshwater flooding. On August 25th, Harvey was upgraded to a devastating Category 4 hurricane, when sustained wind speeds topped 215 kph.

Since making landfall on Friday and stalling over Texas (Louisiana is also affected) – despite being downgraded to a tropical storm as it weakened – it has broken records of it’s own. “No hurricane, typhoon, or tropical storm, in all of recorded history, has dropped as much water on a single major city as Hurricane Harvey is in the process of doing right now in Houston (Texas)”, reports Forbes. In fact, the National Weather Service had to update the colour charts on their graphics in order to effectively map it. This visualisation maps Harvey’s destructive path through Texas.

A snaptshot from the tweet by the official Twitter account for NOAA’s National Weather Service.

So far the death toll is reported to be between 15 to 23 people, with the Houston Police Chief saying 30,000 people are expected to need temporary shelter and 2,000 people in the city had to be rescued by emergency services (figures correct at time of writing).

Many factors contributed toward making Hurricane Harvey so destructive. “The steering currents that would normally lift it out of that region aren’t there,” J. Marshall Shepherd, director of the atmospheric sciences program at the University of Georgia, told the New York Times. The storm surge has blocked much of the drainage which would take rainfall away from inland areas. And while it isn’t possible to say climate change caused the hurricane, “it has contributed to making it worse”, says Michael E Mann. The director of the Earth System Science Center at Pennsylvania State University argues that rising sea levels and ocean water temperatures in the region (brought about by climate change) contributed to greater rainfall and flooding.

A man carries his cattle on his shoulder as he moves to safer ground at Topa village in Saptari. Credit: The Guardian.

While all eyes are on Houston, India, Bangladesh and Nepal are also suffering the consequences of devastating flooding brought about a strong monsoon. The United Nations estimates that 41 million people are affected by the disaster across the three countires. Over 1200 people are reported dead. Authorities are stuggling with the scale of the humanitarian crisis: “Their most urgent concern is to accessing safe water and sanitation facilities,” the UN Office for the Coordination of Humanitarian Affairs (OCHA) said earlier this week, citing national authorities. And its not only people at risk. Indian authorities reported large swathes of a famous wildlife reserve park have been destroyed. In Mumbai, the downpour caused a building to collapse killing 12 people and up to 25 more are feared trapped.Photo galleries give a sense of the scale of the disaster.

Districts affected by flooding. Credit: Guardian graphic | Source: ReliefWeb. Data as of 29 August 2017

What you might have missed

In fact, it’s highly unlikely you missed the coverage of this month’s total solar eclipse over much of Northern America. But on account of it being the second biggest story this month, we felt it couldn’t be left out of the round-up. We particularly like this photo gallery which boasts some spectacular images of the astronomical event.

This composite image, made from seven frames, shows the International Space Station, with a crew of six onboard, as it transits the Sun at roughly five miles per second during a partial solar eclipse, Monday, Aug. 21, 2017 near Banner, Wyoming. Credit: (NASA/Joel Kowsky)

Since the end of July, wildfires have been raging in southwest Greenland. While small scale fires are not unheard of on the island otherwise known for its thick ice cap and deep fjords, the fires this month are estimated to extend over 1,200 hectares. What started the fires remains unknown, as do the fuel sources and the long-term impacts of the burn.

The U.S.A’s National Oceanic and Atmospheric Administration highlighted that the fires are a source of sooty “black carbon”. As the ash falls on the pristine white ice sheet, it turns the surface black, which can make it melt faster. Greenland police recently reported that unexpected rain haf all but extinguished the massive fires; though the situation continues to be monitored, as smouldering patches run the risk of reigniting the flames.

 

 

 

Links we liked

The EGU story

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