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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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From today, until 8 Sep 2017, you can suggest:

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Imaggeo on Mondays: An epic ‘house’ move across the ice

Imaggeo on Mondays: An epic ‘house’ move across the ice

In 2008 the NEEM Deep Ice Core Project was initiated by 14 partner countries in Northwestern Greenland (camp position 77.45°N 51.06°W) with the aim to drill from the very top of the  Greenland ice cap to its base; obtaining  ice from as far back as the last interglacial period- the Eemian – some 130,000 years old.

At the start of the 2008 field season, the NEEM camp consisted of a single heavy-duty tent, some vehicles, and a skiway. Over the summer months, the facilities could host up to 30 researchers at a time. Extra heavy duty tents were built to accommodate everyone comfortably. However to further ease the work of the many researchers who contributed to the project over several years and to create a common space, ‘the dome’ was build. Spread over three stories, the round black building included a kitchen and eating space on the ground floor, a working and relaxing area on the first floor for and a top floor for observing weather conditions before incoming flights.

After three summers of drilling through the icecap, bedrock was reached in 2010 and the Eemian ice was secured.

The 2011 season was spent on surface programs and some drilling into bedrock. Finally, in 2012 the deep ice core drilling project NEEM was terminated and camp was dismantelled.  Most of the heavy equipment was left on the NEEM site with supplies and equipment stored inside the main dome, in two garages, and on seven heavy sleds. The large dome was put on skis with the intention of moving it to the next drilling site, though exactly where was yet to be determined and  funds also needed to be secured.

In 2015, a group of 12 people, including myself, travelled back to the NEEM site. We packed down the the garages and stored them on sledges, we removed 3 years’ worth of accumulated snow (~1.5 m) from the sledges packed in 2012 and from the 45 ton main dome, and finally made the whole lot ready for moving.  Using specialist snowploughs (known as a PistenBully, sponsored by NSF ) we relocated to our new drilling site, EastGRIP at the North East Greenland Ice Stream (NEGIS).

The trip began on Monday 18th May in the afternoon. Progress was slow. By 20.30 the traverse consisting of 8 vehicles had traveled 24 km along the ice flow divide towards the south-east, towing an incredible  143 tonnes worth of equipment, not including the weight of the vehicles themselves.

After an arduous eight day traverse, on 26th May the convoy made the last 53 km of the journey and arrived at EastGRIP in the afternoon. On arrival, the team only had 3000 litres of fuel left, which would have only supported the traverse for one more day. The total route travelled was 449 km.

The focus of the work at the new ice core camp at EastGRIP is different to that of the NEEM project. While the overall aim is to also drill to the bottom of the Greenland ice sheet, this time the goal is to understand the fast flowing ice at NEGIS.

Ice streams, such as NEGIS, are responsible for draining a significant fraction of the ice from the Greenland Ice Sheet. By drilling to the bottom of the ice sheet the project hopes to gain new and fundamental information on ice stream dynamics, thereby improving the understanding of how ice streams will contribute to future sea-level change. The drilled core will also provide a new record of past climatic conditions from the northeastern part of the Greenland Ice Sheet which will be analysed at numerous laboratories worldwide. Similar to NEEM the project has many international partners and is managed by the Centre for Ice and Climate, Denmark with air support carried out by US ski-equipped Hercules aircraft managed through the US Office of Polar Programs, National Science Foundation.

By Helle Astrid Kjær, researcher at the Niels Bohr Institute,  University of Copenhagen

 

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: Heavy machinery

Imaggeo on Mondays: Heavy machinery

How do you get heavy machinery, such as a drill spool onto an ice sheet? This week’s imaggeo on Mondays’ photography captures the freighting of components of a hot water drill to directly access and observe the physical and geothermal properties at the ice-bed interface. In the image, SAFIRE principal investigator Bryn Hubbard and post-doc Sam Doyle help fly in the drill spool at the start of the Summer 2014 field campaign on Store Glacier, Western Greenland.

Freighting several tons of equipment onto the Greenland Ice Sheet for the sake of science may be slightly intense, but in doing so, it reveals an environment that is complex in history and dynamics.

The Greenland Ice Sheet is losing mass at an increasing rate, and since 2010 has contributed 1 mm/year to global sea level rise. The large majority of changes occur within the drainage basins of marine-terminating glaciers (those which end at the lands edge and drain into the sea), which flow rapidly and drain 88% of the ice sheet. While the surface melt processes of glaciers has been well-studied and quantified, very little is known about what happens below the glacier surface, especially where the ice meets the bedrock.

Recent studies from Greenlandic outlet glaciers have emphasized meltwater-enhanced basal lubrication as an increasingly important mechanism to explain the flow of ice down a glacier. In essence, meltwater generated at the glacier surface will eventually find its way down to the glacier bed through crevasses that connect these two systems. The sudden influx of water increases the pressure within the environment, causing the glacier to “lift” off the bed and flow faster. However, the mechanism is largely an untested theory, and its specifics at the ice-bed interface are still largely unknown, especially on fast-flowing outlet glaciers. In order to achieve accurate predictions of sea level rise in the near future, we need to fully understand the dynamics occurring at the ice-bed interface and its complex response to climate-induced ice melt.
Obviously, a great method to tackle this research question is to air freight tons of heavy machinery onto the Greenland Ice Sheet, and to gain access to the bed of the ice sheet by drilling a 600-metre tunnel with hot water. This is part of the Subglacial Access and Fast Ice Research Experiment (SAFIRE), a collaboration between the Scott Polar Research Institute at the University of Cambridge and Aberystwyth University in Wales.

The SAFIRE project has two specific goals: 1. to identify and characterise the mechanical and hydrological conditions at the base of a large outlet glacier in Greenland, using instruments installed in boreholes drilled to the bed; and 2. to determine the role of basal processes in governing ice flow and iceberg calving. With no previous observation ever made in a subglacial environment of this type of glacier, this project breaks new ground, and from the unique datasets acquired from instruments deployed in boreholes and on the glacier’s surface, higher order numerical ice-flow models can be written and constrained.

Our work is mainly on Store Glacier, which is a large tidewater glacier in the Uummannaq region of northwestern Greenland. Store has a large drainage basin (35,000 km2) and flows up to 5 km/year at the glacier terminus, discharging extremely large volumes of ice into the ocean every day. Since 2014, we have been working on-site at a campsite ~30 km from the terminus, and our results characterise an extremely dynamic and warm basal environment over a deformable sediment bed. A detailed analysis of these unexpected results will be forthcoming in the near future.

By TJ Young, Scott Polar Research Institute / British Antarctic Survey 

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: Just Passing

Imaggeo on Mondays: Just Passing

If lucky enough to visit Ilulissat Icefjord, you’d find yourself in a truly ancient landscape. From the up to 3.9 billion year old Precambrian rocks, to ice dating back to the Quaternary Ice Age (2.6 thousand years old) and archaeological remains which evidence the past settlement of this remote Greenlandic outpost, it’s no surprise this stunning location has been declared a UNESCO world heritage site.

Today’s Imaggeo on Mondays photograph was taken by Camille Clerc, at Sermermiut, an old inuit settlement at the mouth of the Ilulissat Icefjord. Located 1,000 km up the west coast of Greenland, in the Bay of Disko Bugt, 250 km inside the Arctic Circle, the icefjord is the sea mouth of Jakobshavn Glacier – one of the few glaciers on Greenland which reaches the sea. Confined either side by ancient Precambrian rocks, the icefjord forms a narrow, 3-6 km wide tidewater ice-stream, where vast amounts of meltwater and ice from the Greenland ice-sheet reach the sea.

Jakobshavn (also known as Sermeq Kujalleq) is Greenland’s fastest moving glacier. Huge chunks of ice break off the glacier front via Ilulissat Icefjord in a process known as glacier calving. Annually, over 35 km3 of ice is calved into the sea; equivalent to 10% of the production of all Greenland calf ice and more than any other glacier outside Antarctica! As a result, there is an almost constant production of icebergs, which vary in size from small lumps to bergs which can exceed 100m height. As they make their way towards the sea, the icebergs actively erode the fjord bed, slowly changing its morphology over time.

The tragic sinking of the Titanic on its maiden voyage, as a result of a collision with an iceberg on the night of the 15th April 1912, is part of modern history and was even portrayed in a Hollywood blockbuster. Could one of the mighty icebergs calved from Jakobshavn via Ilulissat Icefjord, be the culprit of the sinking of the White Star Line vessel? Pinpointing the exact location from which the glacier was calved is tricky. Most icebergs found in North Atlantic waters originate from the western coast of Greenland. They are pushed slowly towards more northerly latitudes by the West Greenland Current and then forced towards the Atlantic, hugging the coast of Canada, by the Labrador Current, eventually making their way to the Gulf Stream, along one of the world’s busiest shipping routes. The journey there is long and more often than not, the icebergs take such battering during the voyage that their original size is much diminished.

 

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/.

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