GeoLog

Geoscientific Methods

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


Carbon dioxide plays a significant role in trapping heat in Earth’s atmosphere. The gas is released from human activities like burning fossil fuels, and the concentration of carbon dioxide moves and changes through the seasons. Using observations from NASA’s Orbiting Carbon Observatory (OCO-2) satellite, scientists developed a model of the behavior of carbon in the atmosphere from Sept. 1, 2014, to Aug. 31, 2015. Scientists can use models like this one to better understand and predict where concentrations of carbon dioxide could be especially high or low, based on activity on the ground. Credit: NASA’s Goddard Space Flight Center/K. Mersmann, M. Radcliff, producers

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 story

Our top pick for October is a late breaking story which made headlines across news channels world-wide. The World Meteorological Organization (WMO) announced that ‘Greenhouse gases in the atmosphere had surged to new records’ in 2016.

“Globally averaged concentrations of CO2 reached 403.3 parts per million in 2016, up from 400.00 ppm in 2015 because of a combination of human activities and a strong El Niño event,” reported the WMO in the their press release.

The last time Earth experienced a comparable concentration of CO2 was 3 to 5 million years ago (around the period of the Pliocene Epoch), when temperatures were 2-3°C warmer and sea level was 10-20 meters higher than now. You can put that into context by taking a look at this brief history of Earth’s CO2 .

Rising levels of atmospheric CO2  present a threat to the planet, most notably driving rising global temperatures. The new findings compromise last year’s Paris Climate Accord, where 175 nations agreed to work towards limiting the rise of global temperatures by 1.5 degrees celsius (since pre-industrial levels).

No doubt the issue will be discussed at the upcoming COP 23 (Conference of Parties), which takes place in Bonn from 6th to 17th of November in Bonn. Fiji, a small island nation particularly vulnerable to rising sea levels and extreme weather phenomena (a direct result of climate change), is the meeting organiser.

What you might have missed

The 2017 Hurricane season has been devastating (as we’ve written about on the blog previously), but in a somewhat unexpected turn of events, one of the latest storms to form over the waters of the Atlantic, took a turn towards Europe.

Storm Ophelia formed in waters south-west of the Azores, where the mid-latitude jet stream push the storm toward the UK and Ireland. By the time it made landfall it had been downgraded to a tropical storm, but was still powerful enough to caused severe damage. Ireland, battered by 160 kmph winds, declared a national emergency following the deaths of three people.

NASA-NOAA’s Suomi NPP satellite took this thermal image of Hurricane Ophelia over Ireland on Oct. 16 at 02:54 UTC (Oct. 15 at 10:54 p.m. EDT).
Credits: NOAA/NASA Goddard Rapid Response Team

The effects of the storm weren’t only felt across the UK and Ireland. In the wake of an already destructive summer fire season, October brought further devastating forest fires to the Iberian Peninsula. The blazes claimed 32 victims in Portugal and 5 in Spain. Despite many of the wildfires in Spain thought to have been provoked by humans, Ophelia’s strong winds fanned the fire’s flames, making firefighter’s efforts to control the flames much more difficult.

On 16th October many in the UK woke up to eerie red haze in the sky, which turned the Sun red too. The unusual effect was caused by Ophelia’s winds pulling dust from the Sahara desert northward, as well as debris and smoke from the Iberian wildfires.

And when you thought it wasn’t possible for Ophelia to become more remarkable, it also turns out that it became the 10th storm of 2017 to reach hurricane strength, making this year the fourth on record (and the first in over a century) to hit that milestone.

But extreme weather wasn’t only limited to the UK and Ireland this month. Cyclone Herwart brought powerful winds to Southern Denmark, Germany, Poland, Hungary and Czech Republic over the final weekend of October. Trains were suspended in parts of northern Germany and thousands of Czechs and Poles were left without power. Six people have been reported dead. Hamburg’s inner city area saw significant flooding, while German authorities are closely monitoring the “Glory Amsterdam”, a freighter laden with oil, which ran aground in the North Sea during the storm. A potential oil spillage, if the ship’s hull is damaged, is a chief concern, as it would have dire environmental concerns for the Wadden Sea (protected by UNESCO).

Links we liked

The EGU story

This month we released not one but two press releases from research published in our open access journals. The finding of both studies have important societal implications. Take a look at them below

Deforestation linked to palm oil production is making Indonesia warmer

In the past decades, large areas of forest in Sumatra, Indonesia have been replaced by cash crops like oil palm and rubber plantations. New research, published in the European Geosciences Union journal Biogeosciences, shows that these changes in land use increase temperatures in the region. The added warming could affect plants and animals and make parts of the country more vulnerable to wildfires.

Study reveals new threat to the ozone layer

“Ozone depletion is a well-known phenomenon and, thanks to the success of the Montreal Protocol, is widely perceived as a problem solved,” says University of East Anglia’s David Oram. But an international team of researchers, led by Oram, has now found an unexpected, growing danger to the ozone layer from substances not regulated by the treaty. The study is published in Atmospheric Chemistry and Physics, a journal of the European Geosciences Union.

GeoTalk: Drilling into the crater which contributed to the demise of dinosaurs

GeoTalk: Drilling into the crater which contributed to the demise of dinosaurs

Six months ago, somewhere in the tropical waters off the coast of Mexico, scientists began drilling into one of the most iconic geological features on Earth: the Chicxulub crater; the 66 million year old remnants of a deadly asteroid impact, thought to have contributed to the demise of dinosaurs and most other forms of life which inhabited the Earth at the time.

Today we speak to Sonia Tikoo, Assistant Professor of Planetary Sciences, Department of Earth and Planetary Sciences, Rutgers University, and one of the researchers part of an international team which is currently trying to decipher the secrets held by the rocks of the Chicxulub crater at a core repository in Bremen.

First, could you introduce yourself and tell our readers a little more about your career path so far?

In general, my work involves using the magnetism recorded within rocks to understand problems in the planetary sciences.  I started doing research in palaeomagnetism during college but I really wanted to work in something involving space so I transitioned into planetary science during graduate school.  During my PhD at MIT, I worked on studying the palaeomagnetism of lunar rocks from the Apollo missions to understand the history of the now-extinct lunar dynamo magnetic field.  It was really cool to explore the different ways that small planetary bodies could also generate long-lived magnetic fields lasting a billion years or more.  I subsequently started studying how shock and impact cratering events affect magnetic records within rocks during my postdoc at UC Berkeley, and that experience eventually led me to the work on Chicxulub that I’m doing right now!

Meet Sonia, pictured with colleague William Zylberman, holding up some samples collected from the IODP cores.

Meet Sonia, pictured with fellow palaeomgnetist William Zylberman, holding up some samples collected from the IODP cores.

For those readers who may not be so familiar with the project, could you give us a whistle-stop tour of aims of the research and why it’s important?

In addition to being the crater linked to the demise of the dinosaurs (cool in and of itself!), Chicxulub is also the best-preserved impact structure on Earth and it is the only crater with an intact and well-defined peak ring (a ring of elevated topography within the crater that forms during the collapse stage of crater modification).  As part of IODP/ICDP Expedition 364, we are planning to address a lot of questions regarding this crater, including: (1) how peak rings (stay tuned for our paper on that which is coming out very soon!), (2) how rocks are damaged or weakened by impact shock, (3) how much hydrothermal circulation occurs after the impact, and how long it lasts, and (4) how life recovered within and above the crater following the impact and Cretaceous-Paleogene extinction?

In terms of my specific job…studying the palaeomagnetism of rocks from the crater can be used as a powerful tool to answer some of the aforementioned questions because the magnetizations within rocks can be modified by high temperatures and pressures, and new magnetic minerals can form via hydrothermal activity.  All of these things happen during large impacts on Earth and on other bodies as well, and we see these effects in the crustal magnetism of planetary surfaces.  The entire Science Party is going to be quite busy working on these problems over the next couple years.  What we learn here is not only going to tell us about Chicxulub but also about peak-ring basins across the solar system, and as a planetary scientist I find that angle to be particularly exciting.

What is your role specific role in the project?

Sonia is pictured drilling into cores from the IODP 364 Expedition, to collect smaller samples for palaeomagnetic experiments.

Sonia is pictured drilling into cores from the IODP 364 Expedition, to collect smaller samples for palaeomagnetic experiments.

I’m serving as a palaeomagnetist on the expedition.  There are two groups of scientists associated with Expedition 364 – the Offshore Science Party (the team that recovered the core at sea) and the Onshore Science Party (the team that conducts sampling and preliminary analyses here in Bremen). There wasn’t a magnetometer on the drilling vessel, so I became a member of the Onshore Science Party.  My job here is to collect samples and develop a first-pass dataset of measurements that characterizes the magnetization of the various rock units in the core, spanning both the post-impact sediments and the underlying impactite rocks. The sediment data will eventually be used for magnetostratigraphy and to develop an age model for the post-impact period, and the impactite data gives us a sneak peek at what we will be working with in much greater detail during our post-expedition research as we try to understand the different types of magnetization present in the crater’s peak ring.

So, the experiments are taking place right as we speak?! Can you tell us more about what it is like working at the core repository?

Yes, they are running right now!  Working on an IODP/ICDP expedition is a totally intense, totally rewarding experience!  The Onshore Science Party here in Bremen involves around 45 members of the Onshore Science Party and a team of IODP scientists and technicians working together continuously for a month.

First, one team splits the large drill core into halves.  The core halves then get passed onto teams that do detailed visual descriptions of the cores and some physical properties measurements.

Then the core goes to the sampling room, where we collect specimens for both the immediate measurements we are conducting here in Bremen as well as for the post-expedition research that the Science Party members will be conducting at their home institutions.

Starting bright and early at 7:30 every morning, I drill and prepare sample plugs for moisture and density, P-wave, and paleomagnetic analyses. In the afternoons, I usually shift over to processing magnetic data and writing reports while another paleomagnetist, William Zylberman, conducts measurements in the lab.

The final IODP report writing team. (Credit: Sonia Tikoo)

The final IODP report writing team. (Credit: Sonia Tikoo)

Of course, every other team like physical properties, petrology, biostratigraphy, or geochemistry is doing the same kind of fast-paced work in their own way and we’re always comparing notes and taking advantage of our built-in collaborations. Some scientists have been working on Chicxulub or the K-Pg boundary for decades and others of us (like me!) are first-timers.

There is a fantastic energy associated with having so many talented scientists with all these different avenues of expertise working closely together (and trying to get everything done before our month here is over)!

 

If you want to learn more about the IODP Expedition and associated research, you’ll find some resources here:

 

Geotalk is a regular feature highlighting early career researchers and their work.

Geosciences column: Making aurora photos taken by ISS astronauts useful for research

Geosciences column: Making aurora photos taken by ISS astronauts useful for research

It’s a clear night, much like any other, except that billions of kilometers away the Sun has gone into overdrive and (hours earlier) hurled a mass of charged particles, including protons, electrons and atoms towards the Earth.  As the electrons slam into the upper reaches of the atmosphere, the night sky explodes into a spectacular display of dancing lights: aurora.

Aurora remain shrouded in mystery, even to the scientists who’ve dedicate their lives to studying them. Photographs provide an invaluable source of data which can help understand the science behind them. But, for aurora images to be of scientific value researchers need to know when they were taken and, more importantly, where.

You’ve got to be in the right place at the right time to catch a glimpse of the elusive phenomenon. In the Northern Hemisphere, aurora season peaks in autumn through to winter. Geographically, the best chance of seeing them is at latitudes between 65 and 72 degrees – think the Nordic countries.

That is unless you are an astronaut on the International Space Station (ISS), in which case, you’ve got the best seat in the house!

The orbit of the ISS means it skims past the point at which aurora intensity is at its peak, which also happens to be the point at which they look their most spectacular. Its orbital speed means it can get an almost global-scale snapshot of an aurora, passing over the dancing lights in just under 5 minutes.

Not as much is known about Aurora Australis (those which occur in the southern hemisphere) as we do about the Northern Lights (visible in the northern hemisphere), because there are far less ground-based auroral imagers south of the equator. The ISS orbit means that astronauts photograph Aurora Australis almost as frequently as Aurora Borealis, helping to fill the gap.

Testament to the privileged viewpoint is the hoard of photographs ISS astronauts have amassed over time – perfect for scientists who study aurora to use in their research.

Time-lapse shot from the International Space Station, showing both the Aurora Borealis and Aurora Australis phenomena. Credit: NASA

Except that, until recently, the ISS photographs were of little scientific value because they aren’t georeferenced. The images are captured by astronauts in their spare time using commercial digital single lenses reflector cameras (DSLRs), which can’t pinpoint the location at which the photographs were taken – they were never intended to be used in research.

Now, researchers at the European Space Agency (ESA) have developed a method which overcomes the problem. By mapping the stars captured in each of the photographs and the timestamp on the image (as determined by the camera used to take the photograph), the team are now able to geolocated the images, giving them accurate orientation, scale and timestamp information.

Despite the success, it’s not a straightforward thing to do. One of the main problems is that the timestamps aren’t always accurate. Internal clocks in DSLRs have a tendency to drift. Over the period of a week they can be out by as much as a minute, making it difficult to establish the location of the ISS when the image was captured. This has implications when creating the star map, as the location of the station is used as a starting point.

To resolve the issue, aurora images which also include city lights can be aligned to geographical maps using reference city markers to get a timestamps accurate to within one second or less. In the absence of city lights, images which also capture the Earth’s horizon are aligned with its expected position instead. The correction works best if both city lights and the horizon can be used.

Errors are also introduced when the star maps can’t be fully resolved (due to the original image being noisy, for example) and because the method assumes that auroras originate from a single height, which isn’t true either.

detailed comparison between the ISS image plotted in Fig. 11 (b) and the contemporaneous image acquired by the SNKQ THEMIS ASI (a) . The original ISS image is plotted in (c) . Red and blue symbols trace the locations of the j shaped arc and northern edge of the main auroral arc, respectively, derived from their locations in the THEMIS image. The features are marked with the same coloured arrows in (c) . The magenta arrows point out a vertical feature projected very differently in (a) and (b) .

A detailed comparison between an ISS image of aurora (a) plotted and (b) the contemporaneous image acquired by the SNK THEMIS ASI [ground-based]. The original ISS image (a) is plotted in (c). For more detail see Riechert, et al., 2016.

Comparing images of an aurora on 4 February 2012, captured both by the ISS crew and a ground-based instrument, has allowed the researchers to test the accuracy of their method. Overall, the results show good agreement, but highlight that the projection of the ISS images has to be taken into account when interpreting the results.

Now, a trove of thousands of Aurora Borealis and Australis photographs can be used by researchers to decipher the secrets of one the planet Earth’s most awe-inspiring phenomenon.

By Laura Roberts Artal, EGU Communications Officer

 

References:

Riechert, M., Walsh, A. P., Gerst, A., and Taylor, M. G. G. T.: Automatic georeferencing of astronaut auroral photography, Geosci. Instrum. Method. Data Syst., 5, 289-304, doi:10.5194/gi-5-289-2016, 2016.

Automatic georeferencing of astronaut auroral photography: http://www.cosmos.esa.int/web/arrrgh

The research was accomplished using only free and open-source software. All the images processed to date are made freely available at htttp://cosmos.esa.int/arrgh, as is the software needed to produce them.

Celebrating Earth Science Week!

Celebrating Earth Science Week!

For those not so familiar with the Earth sciences, geosciences and all its subdisciplines might be shrouded in mystery:  boring, unfathomable, out of reach and with little relevance to everyday life. Nothing could be further from the truth!

Earth Science Week, an international annual celebration founded by the American Geosciences Institute in 1998, aims to change the public’s perception of the geosciences.  Since 2011, the London Geological Society also hosts a range of events and activities to raise awareness and better understanding of the Earth sciences.

In 2016, Earth Science Week takes place between 8 and16 October. For the first time, the EGU will run events to mark the special date, all of which we invite you to take part in!

Earth Science Week Photo Competition

From Wednesday 5th to Friday 14th October submit an original photo on any broad theme related to the Earth, planetary and space sciences to our open access image repository, Imaggeo.

For your image to be included in the competition be sure to include the tag #EarthSciWeek when prompted during the upload.

Upon the submission period closing, all entered images will be published to the EGU’s Facebook page. The photograph with most likes, as chosen by the public, will be crowned the competition winner.

The winner will get one free book of their choice from the EGU library and a pack of EGU goodies! We’ll also feature the top five most popular entries on our Instagram.

I’m a geoscientist – Ask me Anything: Live Twitter Q&As

Have you always wanted to know how glaciers move and carve out unbelievable landscapes? How about which emissions cause the most pollution? What are the benefits of publishing in an open access journal vs. a pay-walled publication? If politicians make all the decisions, how can we get them to take scientists more seriously?

If you’ve ever asked yourself these questions, stay tuned or, better still, take part in our daily Earth Science Week live #EGUchat with an EGU member on Twitter. Starting on Monday, every lunchtime, you’ll have the opportunity to put your questions to a range of scientists and EGU experts and discuss a variety of subjects.

Our very own Sarah Connors (@connors SL), the EGU’s Policy Fellow, will kick off a week, of what we hope will be fruitful discussions, by taking questions on all things science policy. Come Tuesday Emma Smith (@emma_c_smith) and Nanna Karlsson (@icymatters), Cryosphere Division Blog editors, will team up to shed light on the processes which operate in the iciest places on the planet.

Wednesday brings editor of the EGU’s open access journal Earth Surface Dynamics (ESurf) and Professor of Physical Geography at the University of Hull, Tom Coulthard (@Tom_Coulthard), who will shed light on the processes which shape our planet and the trials and tribulations of getting published.

If you are interested in natural hazards, how we mitigate, manage them and how they impact on our daily lives, then tune in to the chat on Thursday, where Giorgio Boni (@EguNHpresident), President of the Natural Hazards Division will be answering all your questions!

For the final chat of the week, we bring you Michelle Cain (@civiltalker), an atmospheric scientist and former Atmospheric Division Early Career Scientist Representative. Michelle will be taking questions on gaseous emissions and topics related to the Earth’s atmosphere.

Joining the conversation couldn’t be easier! To put your questions to our experts follow the hashtag #EGUchat on Twitter. Not on twitter or aren’t available during the chats? Not to worry, send us your questions in the comments below or via Twitter, Facebook or Instagram: we’ll ask the experts on your behalf.earth_sci_week_ama_twitter-01