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January GeoRoundup: the best of the Earth sciences from across the web

January Georoundup: the best of the Earth sciences from across the web

The start of the new year sees the launch of a new series here on GeoLog. 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

One of the biggest stories of this month was the anticipated release of the average global surface temperatures for 2016. It probably wasn’t a great surprise to discover that newly released National Oceanic and Atmospheric Administration (NOAA), NASA and the UK’s MetOffice data showed 2016 was the hottest year on record. On average, temperatures last year were 0.99℃ higher than the mid-century mean. It marks the third year in a row that Earth has registered record-breaking temperatures and highlights a trend, as climate blogger, Dana Nuccitelli, explains in an article for The Guardian:

“We’re now breaking global temperature records once every three years”

This video, showing NASA global surface temperature record since 1880, illustrates the point clearly. There were no record breaking years between 1945 and 1976, but since 1980 there have been 12.

 

This month also saw the inauguration of the 45th President of the United States. A fierce climate-change denier, Donald Trump’s rise to power has many worried about the future of climate change policy at the White House. To shine a light on the realities of climate change in the face of a largely climate sceptic administration and despite the ever rising global temperatures, The Guardian dedicate 24 hours to reporting on how climate changes is affecting regions across the globe. Among the comprehensive coverage this collection of climate facts stands out.

And it turns out the fears about the newly elected administration may not have been unfounded. Earlier this week the US Department of Agriculture and other federal agencies issued a ban preventing its scientists from communicating with the press and public about their research findings; even on social media. The order has since been rescinded, but US- based scientists remain concerned. In response, the AGU has written a letter to federal agencies in the US defending the protection of scientific integrity and open communications.

Closer to home, central Italy was struck by a sequence of four earthquakes on 18th of January, with the largest registering a magnitude of 5.7. The epicentres were located close to the town of Amatrice – in a region already shaken by several strong, and sometimes devastating, earthquakes in 2016. Later that day, and following a period of very heavy snowfall, a deadly avalanche in the Apennines buried a hotel in the Grand Sasso resort area, which had also been affected by the earthquakes. Although some news reports were quick to suggest the avalanche had been triggered by the earthquakes, researchers will need more data and a more detailed analysis to make this connection.

What you might have missed

While we are on the topic of climate change, a newly published report by the  European Environmental Agency is not to be missed.

“Climate change poses increasingly severe risks for ecosystems, human health and the economy in Europe.”

The document assesses the latest trends and projections on climate change and its impacts across Europe. While the effects of increasing temperatures will be felt across the continent, Southern and south-eastern Europe is projected to be a climate change hotspot with the forecasts showing the region will bear the brunt of the impacts.

A powerful 7.9 magnitude earthquake struck off the coast of Papua New Guinea on 22nd January. While the USGS estimated there was a low risk to property, tsunami warnings were issued across the South Pacific. In the wake of the tremor, the Incorporated Research Institutions for Seismology (IRIS) tweeted this neat ground motion visualisation of the earthquake waves.

A study published in Nature and summarised in Eos, highlights that while overt discrimination of women in the geosciences has not been as prevalent in recent years, many female scientists are still subject to subtle and unconscious bias leading to barriers to success in the geosciences.

Five links we liked

  • NOAA’s new GOES-R satellite for weather monitoring returned its first stunning photos of planet Earth – here are six reasons why the data it will acquire matter.
  • Snow fell in the Sahara for the first time in 37 years! This photogallery shows the usually red sand dunes of the desert covered in a sprinkling of white snow.
  • Scientist at The University of Cambridge have published the first global map of flow within the Earth’s mantle, showing that the surface moves up & down “like a yo-yo”.

The EGU story

At the EGU, the highlight of the month is the number of abstracts we received from researchers wishing to present and discuss their science at the EGU 2017 General Assembly. With over 17,500 abstracts, and an improved set-up to accommodate the high number of expected participants, the conference promises to be the largest and most exciting to date. We look forward to welcoming everyone in Vienna on 23–28 April!

And don’t forget! To stay abreast of all the EGU’s events and activities, from highlighting papers published in our open access journals to providing news relating to EGU’s scientific divisions and meetings, including the General Assembly, subscribe to receive our monthly newsletter.

A first-timer’s guide to the 2017 General Assembly

A first-timer’s guide to the 2017 General Assembly

Will this be your first time at an EGU General Assembly? With 13,650 participants in a massive venue, the conference can be a confusing and, at times, overwhelming place.

To help you find your way, we have compiled an introductory handbook filled with history, presentation pointers, travel tips and a few facts about Vienna and its surroundings. Download your copy of the EGU General Assembly guide here!

Announcing the winner of the EGU Best Blog Post of 2016 Competition

Announcing the winner of the EGU Best Blog Post of 2016 Competition

There is no doubt that 2016 was packed full of exciting, insightful and informative blog posts. An impressive 360 posts were published across the EGU’s official blog, GeoLog, as well as the network and division blogs!

In December, to celebrate the excellent display of science writing across the network and division blogs, we launched the EGU Blogs competition. From a list of posts selected by our blog editors, we invited you, the EGU Blogs readers, to vote for your favourite post of 2016. After a little over three weeks of voting, the winners are finally in!

Without further ado, we’d like to extend a big congratulations to the Cryosphere Blog, who take this year’s crown, with a 58% share of the votes, for their post following the journey of a snowflake! From the water vapour in a cloud to the snowman in your garden, find out what leads to the complex structure you can see on in the image below!

Snowflakes viewed with a low temperature scanning electron microscope (SEM). [ Image Credit : Agricultural Research Service, United States Department of Agriculture via Wikimedia]

All the posts entered into the competition are worthy of a read too, so head over to the poll and click on the post titles to learn about a variety of topics: from the fate of Fukushima Iodine-129 in rain and groundwater, to exploring whether letters of recommendation are the key to the leaky pipeline in academia and how common soft sediment structures like slumps and flames form.

If the start of a new year, with its inevitable resolutions, along with the range and breadth of posts across the EGU Blogs have inspired you to try your hand at a little science writing then remember all the EGU Blogs welcome (and encourage!) guest posts.  Indeed, it is the variety of guest posts, in addition to regular features, which makes the blogs a great read! If you would like to contribute to any of the network, divison blogs or GeoLog, please send a short paragraph detailing your idea to the EGU Communications Officer, Laura Roberts at networking@egu.eu.

 

Shaking on Christmas Day: what we know about the 7.6 M Chile earthquake

Chile, Chiloe earthquake

While the majority of us were midway through our Christmas Day celebrations, a powerful 7.6 M earthquake struck off the western coast of the Chile. Natural hazards are not bound by time, location or festivities; an earthquake can happen at any time in any place, regardless of the significance of the day. As a result, in this earthquake prone region, raising awareness of the risk posed by natural hazards is vitally important.

The Christmas Day quake struck 42 km south west of the port city of Quellón, on the rural island of Chiloé at a depth of 34 km. Despite the powerful shaking, the tremor caused no casualties and damage to infrastructure was limited. For a time, services (such as water and power) to the southern tip of Chiloé were cut. Most affected were roads and bridges, particularly the recently renovated highway 5, which links Quellón with the fishing town of Chonchi.

The earthquake triggered a tsunami warning, leading to the evacuation of 4000 people in the coastal areas of Los Lagos Region, including the towns of Quellón and Chonchi. However, no tsunami waves were reported and the warning was lifted some 90 minutes after the temblor.

Chile’s long history of powerful earthquakes

As recently as September 2015, an 8.3 M tremor hit Illapel, causing 13 casualties, 6 missing and triggering a 4.5 m tsunami wave, with shaking felt as far as Bolivia and Argentina.

A powerful, and destructive, 8.8 M quake struck Maule in February 2010. On land, there was severe loss to infrastructure and housing, while a tsunami wave caused significant damage to coastal areas. Combined, the earthquake and tsunami resulted in the deaths of more than 500 people.

The most powerful tremor ever recorded, the estimated 9.5 M Valdivia earthquake, struck Chile in May 1960. More than 2,000 people were reported dead, a further 3,000 went missing and over 2,000,000 were left homeless. The damage in Southern Chile alone amounted to over $550 million. Tsunami waves generated by the quake struck Hawaii, Japan, the Philippines and the western USA coast, causing a further $50.5 million in damages and killing 231 people.

Damage to houses after the Valdivia earthquake, Chile

Damage to several houses in Chile after the earthquake. Credit: Pierre St. Amand – NGDC Natural Hazards Slides with Captions Header, Public Domain (distributed by Wikimedia Commons)

What causes earthquakes in Chile and what does the future hold?

Chile lies along the Pacific Ring of Fire, an area known for its high seismic and volcanic activity. Here, tectonic plates slide against each other, pull apart or converge and subduct under one another generating geologically active zones.

To understand why powerful earthquakes occur in Chile, we asked Cindy Mora Stock, a seismologist at the University of Concepción (Chile), to give us a more detailed insight into the tectonics of the region:

Earthquakes along the Chilean coast occur at the interface between the South American plate and the subducted Nazca plate. The rapid velocity between these plates (66 – 90 mm/yr) increases the potential for great earthquakes in the region, presenting on average an event of magnitude 8, or larger, every ten years. As a comparison, the Antarctic plate subducts under South American plate at a much slower rate (16 – 22 mm/yr).

The latest Mw 7.6 earthquake near Quellón on 25th of December [1], falls in the central part of the rupture zone (the portion of the fault which slipped during) of  the Valdivia earthquake – roughly 380 km south from Valdivia.

A study by Lange et al in 2007 showed a cluster of four main 4.0 < Ml < 4.4 events and their afteshocks, occurring at the interface between 12-30 km depth, beneath the western coast of Chiloe Island. Another study by Moreno et al in 2011 shows some patches at the interface that ruptured during the previous 1960 event, which are more stuck than other areas at the same interface.

Especially, computer simulations show the interface at the center part of the 1960’s rupture zone is fully locked, this means that part is “stuck”, not moving, and accumulating energy. Zones that present a high locking rate have shown to be prone areas for the nucleation of a great earthquake in the future. Although in all presented scenarios the Chiloe Island presents a high locking rate, this is not enough to state a range of time when an earthquake will occur at this patch.  Considering this, the previous seismicity, and the present Mw7.6 earthquake in the region it might seem like the interface might have ended its and it is starting to build up stress for a future earthquake.

By Laura Roberts, EGU Communications Officer, and Cindy Mora Stock, postdoctoral researcher at the University of Concepcion, Chile.

 

References and further reading

[1] Intensities of shaking felt after the 25 December earthquake (in Spanish): http://www.sismologia.cl/events/sensibles/2016/12/25-1422-28L.S201612.html

[2] Lange, D., Rietbrock, A., Haberland, E., et al.: Seismicity and geometry of the south Chilean subduction zone (41.5°S–43.5°S): Implications for controlling parameters, Geophysical Research Letters, 34, L06311, doi: 0.1029/2006GL029190, 2007

[3] Moreno, M., Melnick, D., Rosenau, M., et al.: Heterogeneous plate locking in the South–Central Chile subduction zone: Building up the next great earthquake, Earth and Planetary Research Letters, 305, 3-4, 413-424, doi: 10.1016/j.epsl.2011.03.025, 2011 (Paywalled)

USGS overview of M7.6 – 42km SW of Puerto Quellon, Chile (includes shake maps, regional tectonic information and moment tensor details): http://earthquake.usgs.gov/earthquakes/eventpage/us10007mn3#executive

Understanding Tectonic Processes Following Great Earthquakes (Eos: Earth & Space Science News)

25 December earthquake in the news:
·         Chile earthquake tsunami warning lifted (BBC News report)
·         Major quake jolts Chile tourist region on Christmas Day (Reuters in-depth news report)
·         Chile jolted by major 7.6-magnitude earthquake (Guardian News)
·         Imagenes del terremoto al sur de Chile (in Spanish: Images of the earthquake in Southern Chile – Gestión, diario de econimía y negocios de Perú)

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