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Imaggeo on Mondays: Exploring the East African Rift

10 Mar

This week’s Imaggeo on Mondays is brought to you by Alexis Merlaud, an atmospheric scientist from the Belgian Institute for Space Aeronomy. While the wonders of the African atmosphere feature in his photography, the East African Rift has a much bigger tale to tell. Drawing from all aspects of geoscience Alexis shares its story…

Kilimanjaro from Mount Meru. (Credit: Alexis Merlaud, distributed via imaggeo.egu.eu)

Kilimanjaro from Mount Meru. (Credit: Alexis Merlaud, distributed via imaggeo.egu.eu)

This picture shows Kilimanjaro, Africa’s highest mountain, at sunrise. It was taken from Socialist Peak, which marks the top of Mount Meru, some 70 km to the southwest. Both mountains are located in Tanzania and are among the largest stratovolcanoes of the East African Rift Zone. Unlike Kilimanjaro, Meru is active and its most recent eruption occurred in 1910.

Stratovolcanoes, also called composite cones, are built-up by alternating layers of lava flows, pyroclastic rocks, and volcanic ash. During a large eruption, huge quantities of ash and sulphur dioxide can reach the stratosphere, where they can affect the climate for several years, as did the eruptions of Krakatau in 1883 and Pinatubo in 1991. Sulphur dioxide is converted to sulphuric acid droplets, which spread with the ashes throughout the stratosphere. These aerosols screen some of the sunlight, decreasing the average surface temperature by about one degree. The temperature in the stratosphere simultaneously rises by a few degrees, due to the enhanced absorption of sunlight by aerosols.

There is a difference in the tectonic processes associated with these South East Asian volcanoes and the East African Rift: the former are located above a subduction zone while the rift is a divergent boundary.  An example of large volcanic eruption in a divergent zone is the Laki (Iceland) eruption in 1783, which yielded severe meteorological conditions and reduced harvests for several years in Europe. This eruption may have also helped trigger the French Revolution in 1789.

Plate tectonics in East Africa created Kilimajaro and have also played a role in early human evolution, by shaping the local landscape and the long-term climate, thus modifying the environment of our ancestors. East Africa is the area in the world where most of the hominid fossils have been discovered, including Homo sapiens – the oldest fossil record is 200,000 years old and started to move out from Africa 100,000 years ago!

A final thanks: thanks Cristina Brailescu for help climbing Meru and Emmanuel Dekemper for support on editing the picture. 

By Alexis Merlaud, Belgian Institute for Space Aeronomy

Imaggeo is the EGU’s open access geosciences image repository. Photos uploaded to Imaggeo can be used by scientists, the press and the public provided the original author is credited. Photographers also retain full rights of use, as Imaggeo images are licensed and distributed by the EGU under a Creative Commons licence. You can submit your photos here.

Geoscience under the tree

18 Dec

In a festive-themed post, EGU Media and Communications Manager Bárbara Ferreira selects a plethora of geoscience-inspired Christmas presents, which you could give to your favourite researcher. Please note that, with the exception of the last one, the items listed below are not necessarily recommended or endorsed by the EGU.

For me Christmas is more about eating large amounts of food and celebrating with family and friends than it is about giving and receiving presents. But I am guessing many of the readers of this blog are still scratching their heads thinking what gifts to get to the geoscientists in their families, to their Earth or space science researcher friends or, why not, themselves. This, and the fact that Paleoseismicity posted about some beautiful geology shoes a few days ago, is why I’ve set out to discover the best geoscience-inspired gift items out there.

Compiling this list ended up being easier than I thought because a few people, such as Georneys’ Evelyn Mervine and Agile’s Matt Hall have written similar blog posts in the past. And also because I discovered that Etsy – the e-commerce website for all things handmade or vintage – has an impressive collection of geoscience-y items. So, brace yourselves for a link-rich post!

Solid Earth

I’ll start with a present idea for our crafty readers: if you are into knitting, or know someone who is, this book filled with knitted-dinosaur patterns might be for you. If you’re not crafty, you may prefer to gift this triceratops cup or a pair of agate bookends, or even this t-shirt with a different take on the Earth’s internal structure. The geomorphologist in your life might like this antique map illustrating the geomorphology of the Alpine region or this simple yet beautiful travel journal.

If, instead, volcanology is your thing, then you might like this awesome volcano woolly hat – and if you are looking for a gift for a little one, this wooden volcano stacker could be your choice. For soil scientists, Etsy has a collection of beautifully illustrated soil postcards, while tectonic scientists and seismologists, may find this t-shirt funny. This science kit would suit a young fan of rocks and minerals, while this tie with crystalline formations would be more appropriate for a grown up.

Volcano hat by MariaBjork

Volcano hat by MariaBjork

Soft Earth

Moving on to soft-Earth disciplines, atmospheric scientists might like this wonderful screen print of different types of clouds, or this original necklace representing the various layers of the Earth’s atmosphere. And there’s this rather neat calendar of the sky and sea, which may also please ocean scientists. These researchers might also like an ocean tide ceramic pot or a 19th century map of the Atlantic Ocean.

Budding hydrologists, on the other hand, may be fascinated by this hydropower kit, while older ones will likely appreciate this antique engraving of water engineering. On the topic of antiques, the climate scientist in your life may like this climate map of Europe or this beautifully illustrated book to teach kids about climate. When gifting biogeoscientists, you can’t go wrong with this fantastic diatoms t-shirt (available for men and women) or these seaweed magnets.

Diatoms t-shirt by vortextradingcompany

Diatoms t-shirt by vortextradingcompany

Space and planetary science

Moving up into the upper atmosphere, your favourite solar-terrestrial scientist might like to receive this rather cute card of aurora in the Arctic or, for something a bit different, this pair of Northern Lights leggings! Going further up into space, the Earth’s magnetosphere finds its way into this totebag/backpack while the solar corona is the star of this antique print.

Planetary scientists also have plenty to choose from, with a variety of art decals and solar system charts available on Etsy. There is even a seller who builds jewellery with photos from NASA missions, such as this Mars Curiosity Rover pendant. Budding space and planetary scientists will likely be happy with this space exploration kit from National Geographic.

Interdisciplinary areas

Moving on to the more interdisciplinary areas of the EGU, I couldn’t help but mention Slow Factory, who produce stunning (but expensive!) clothing items from satellite images: the Terra MODIS Greenland dress and this silk square with an image of phytoplankton from the Bay of Biscay are two of the highlights. For something a bit more affordable, you could gift this top to bottom poster from Our Amazing Planet (sadly, the original interactive infographic can’t be put up on the wall) or this carbon cycle t-shirt. If you are feeling crafty, you can get LEGOs to build this rather incredible LEGO globe. Energy, resources and the environment enthusiasts have plenty to choose from, from a sustainable Earth lab or a solar-powered night light to a pair of windmill earings or a wind-energy decal. If great waves are more your thing, you may be interested in this tsunami top or, if landslides are your natural-hazard of choice, in this interesting pendant.

If you, like me, prefer to give and receive an experience as a gift, then why not offer a geoscientific trip? Though I haven’t been on a trip of this kind myself, I found a few companies that organise geo-themed excursions, such as this one in Italy, this one in Iceland or this one for trips further afield.

Finally, I couldn’t finish this blog post without suggesting the best present of them all (OK, I’m biased!). This Christmas, why not gift EGU memberships to the Earth, planetary and space scientists in your life? It is very affordable and researchers will likely appreciate the discounted registration rate members receive to the EGU General Assembly!

By Bárbara Ferreira, EGU Media and Communications Manager

Geotalk: Will Morgan on podcasts and polluting the internet

23 Oct

This week in Geotalk, we’re talking to Will Morgan, atmospheric scientist, podcaster and the blogger behind Polluting the Internet

You recently joined the EGU blog network, but you’ve been writing for a while now. What got you blogging?

I guess the ultimate reason is that I enjoy talking about science! I’ve been involved with a number of science communication activities for a few years and blogging is a very popular medium that I wanted to try out. I’ve read scientific blogs since my undergraduate days but the number and range of sites has exploded in recent years. I felt that I would be able to contribute to this and cover aspects that don’t always get as much attention. Aerosol particles might be tiny but they can have big impacts and we have a lot to learn about how they affect our climate and our health.

Will Morgan

Will Morgan. (Credit: Will Morgan)

There’s a wealth of great research out there, how do you choose what to write about?

Mainly through a combination of Twitter, RSS feeds for journals in my field and whatever I happen to be doing that week. Twitter is great for getting ideas, whether that is a new study that has been getting attention in the media or just some spectacular satellite images that routinely appear in your timeline. Scientific conferences are also really helpful for getting ideas as you can cover something “new” that emerges while you are there.

In addition to your science blogging activities, you also run a podcast, together with a host of atmospheric scientists. How did you get started?

As with many ideas in science, the podcast started out with a discussion in a pub. A couple of friends in the atmospheric science group at Manchester thought “wouldn’t it be fun to do an atmospheric science podcast”. They talked to a few of us in the research group and we started getting together to record some episodes and it has continued from there.

You do a lot of podcasting and blogging at conferences and other scientific events, what would you say are the biggest benefits to the public or wider scientific community?

I think it helps to give people an idea of how the process of science actually works – most of the time people see scientists as a talking head on the TV or a few quotes in an article. I’ve found covering conferences a lot of fun as they are often very vibrant affairs with lots of ideas whirling around between groups of passionate people, which maybe isn’t the picture that is usually painted of scientists! I/we have also covered how we go about making measurements in the field, which communicates the challenges of actually doing science and the dedication that is required to do things well. People seem to enjoy listening or reading to these things also, so catering to that audience is really important.

Do you have any tips for people pondering podcasting?

The main tip is to just get on with it and not worry if it doesn’t sound perfect. Most modern mobile phones have the capability to record audio so you can give it a try and put it online (there several free services, such as Podbean for podcasting online). It isn’t going to have the audio quality of a BBC Radio 4 broadcast but that is secondary to the actual content. From there you can develop where you want to go with the podcast and if funds and/or facilities allow, you can get access to better recording equipment or even a studio. Also, the more you do it, the better you get. My only other tip is to not spend too long listening to recordings of your own voice when editing (ideally edit content that you weren’t involved with) as you’ll quickly develop a complex – it was a bit of a shock when I realised that the booming Brian Blessed-esque voice was my own!

Want to know more about what Will’s been up to? Have a read: http://blogs.egu.eu/hazeblog/

Imaggeo on Mondays: Arid lands and ancient lakes

14 Oct

Palaeoclimatologist Annett Junginger takes us to one of the hottest and driest places on Earth in this week’s Imaggeo on Mondays…

“Suguta Showers” by Annett Junginger, distributed by the EGU under a Creative Commons licence.

“Suguta Showers” by Annett Junginger, distributed by the EGU under a Creative Commons licence.

The picture was taken in 2010 during the third in six expeditions to the remote Suguta Valley in the northern Kenya Rift. This unbelievably beautiful place is located just south of Lake Turkana and is one of the hottest and driest places in equatorial Africa. Temperatures often reach 50°C in the shade, but there is no shade. Evaporation is so high that occasional rainfall over the valley escarpments only fills the rivers temporarily, and water often evaporates from the valley slopes faster than it can reach the deepest part of the valley to form a lake. Only during the rainy seasons there is enough water to allow the development of the small Lake Logipi (5 x 10 km across and approximately 3 m deep), which is a key destination for millions of Flamingos.

Due to the remoteness and hostile conditions of the valley, it is largely uninhabited, allowing the perfect preservation of all kinds of geological information. To make the most of this preservation, the Suguta Valley Project has been set up to investigate the valley’s late Cenozoic structural development and lacustrine deposits. The aim is to better understand environmental changes over the course of the region’s volcano-tectonic evolution and the climate fluctuations of the last five million years.

From left to right first row: Lake Logipi during the rainy season; a palaeo-shoreline 300 m above Lake Logipi approximately 10,000 years old (credit: M. Trauth); Lacustrine sediments of the same age. From left to right second row: Flamingos (pink dots) along the shore of Lake Logipi; Mid-Pleistocene lacustrine sediments; Erosion of Holocene lacustrine sediments. From left to right third row: Lake Eight, a maar lake in the southern part of the valley; Sand dunes in the foreground and palaeo-shorelines on the Namarunu volcano in the back; palaeo-shorelines on a small crater in the centre of the valley approximately 5,000 years old. (Credit: Annett Junginger)

From left to right first row: Lake Logipi during the rainy season; a palaeo-shoreline 300 m above Lake Logipi approximately 10,000 years old (credit: M. Trauth); Lacustrine sediments of the same age. From left to right second row: Flamingos (pink dots) along the shore of Lake Logipi; Mid-Pleistocene lacustrine sediments; Erosion of Holocene lacustrine sediments. From left to right third row: Lake Eight, a maar lake in the southern part of the valley; Sand dunes in the foreground and palaeo-shorelines on the Namarunu volcano in the back; palaeo-shorelines on a small crater in the centre of the valley approximately 5,000 years old. (Credit: Annett Junginger)

It may sounds strange that lacustrine deposits can be found here, when the valley experiences such hot and dry conditions. But this is case! Palaeo-shorelines and up to 40 m thick lacustrine sediments are the remains of the huge palaeo-Lake Suguta, 300 m deep and 2,200 km2 large, that existed between 15,000 and 5,000 years ago – from a geological perspective, that’s not long ago at all! We also found lacustrine deposits up to 1 million years old that explain multiple humid periods in the past. The investigation of these palaeo-climate records may help to provide new insights into (1) the spatial and temporal synchronicity of the Early Holocene humid period in East Africa, (2) the role of the tropics in glacial-interglacial transitions during the Pleistocene, and (3) the links between climate changes and human evolution.

By Annett Junginger, Institute for Earth and Environmental Sciences, University of Potsdam

Reference:

Junginger, A., Trauth, M.H., Hydrological constraints of paleo-Lake Suguta in the Northern Kenya Rift during the African Humid Period (15–5 ka BP), Glob. Planet. Change (2013)

Imaggeo is the EGU’s open access geosciences image repository. A new and improved Imaggeo site will be launching soon, so you will be able to peruse an even better database of visually stunning geoscience images. Photos uploaded to Imaggeo can be used by scientists, the press and the public provided the original author is credited. Photographers also retain full rights of use, as Imaggeo images are licensed and distributed by the EGU under a Creative Commons licence. You can submit your photos here.

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