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

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

Drawing inspiration from popular stories on our social media channels, major geoscience headlines, as well as unique and quirky research, this monthly column aims to bring you the latest Earth and planetary science news from around the web.

Major story

The world soaks up the sun

This summer our planet experienced the hottest June in recorded history, with the average global temperature reaching 16.4 °C, and July is on track to becoming the hottest month ever measured on Earth. And if you either live in or have been visiting Europe over the last few weeks, it sure feels like record-breaking heat.

In both June and July, several regions in Europe reached all-time temperature highs as warm air from northern Africa made its way through the continent. A rapid analysis done by researchers affiliated with the World Weather Attribution Network shows that human-caused climate change made the June heatwave at least five times more likely to happen. Furthermore, the scientists say in their report that “every heat wave occurring in Europe today is made more likely and more intense by human-induced climate change.”

Heatwaves this intense can put human health at risk and even be deadly in severe cases. A death toll reported that extreme heat Europe in the summer of 2003 led to more than 70,000 deaths throughout the continent.

The heatwave is now advancing towards Greenland, scientists report, and increased heat in the Arctic will likely lead to “another major peak in melt area,” said Twila Moon, a research scientist with the National Snow and Ice Data Center (NSIDC) in Colorado, US, to Live Science.

Simultaneous to the heatwave, a new study has reported that Earth’s current global warming is the only worldwide climate event to have happened in the last 2,000 years. While there have been notable climate events within the last few centuries, such as dramatic temperature changes from volcanic eruptions, the impact of these events were more regional rather than universal. In contrast, the study finds that modern climate change has affected 98 percent of the world.  “Absolutely nothing resembling modern-day global warming has happened on Earth for at least the past 2,000 years,” said the Atlantic.

50 years since one small step

20 July 2019 also marked the 50th anniversary of the first human steps on the Moon. In 1969, NASA astronauts Neil Armstrong and Buzz Aldrin landed on the Moon’s surface as part of the Apollo 11 Mission, revolutionising our understanding of our closest cosmic neighbor. For the 21 hours and 36 minutes on the lunar landscape, Armstrong and Aldrin reported field observations, installed instruments for multiple experiments, and gathered more than 20 kilograms of rock and dust samples.

Since then, scientists have made several discoveries from the data collected during the Apollo 11 Mission. For example, the rocks brought back from the Moon were determined to be about 4.5 billion years old, not much older than the Earth. Geoscientists also found that rocks from the Moon were very similar chemically to those on Earth, suggesting that the two bodies could have evolved in tandem from a large impact event, a leading theory also known as the giant-impact hypothesis.

Lunar Module pilot Buzz Aldrin photographed during the Apollo 11 extravehicular activity on the moon. Aldrin had just deployed the Early Apollo Scientific Experiments Package. In the foreground is the Passive Seismic Experiment Package; beyond it is the Laser Ranging Retro-Reflector (LR-3). Credit: NASA

While operational, the lunar seismometers installed by Armstrong and Aldrin detected ‘moonquakes’ and revealed that the Moon has a relatively small solid core and a thicker crust compared to the Earths’ interior.

Armstrong and Aldrin also set up a Laser Ranging Retroreflector to precisely measure how close the Moon is to the Earth. The retroreflector is still operational to this day, and the data obtained from the experiment shows that the Moon is almost literally inching away from the Earth at 3.8 centimetres (1.5 inches) each year on average.

These examples are just some of the discoveries made following this mission, and scientists are still studying the samples and data obtained 50 years ago to learn more about the Moon, the Earth and the solar system.

“One of the biggest misconceptions is that the Apollo samples aren’t being studied anymore, and that the Apollo samples only tell us about the moon,” says Ryan Zeigler, Apollo sample curator at the Johnson Space Center, in Science News.

What you might have missed

A new study published in July reported that tidewater glaciers, ones that flow from land to sea, could be melting much faster than previously thought. By analysing detailed measurements collected through radar, sonar and time-lapse photography, a team of researchers found that one Alaskan tidewater glacier is releasing a surprising meltwater from below the surface of the ocean.

“The melt rates that we measured were about 10 to 100 times larger than what theory predicted,” says lead study author David A. Sutherland, an oceanographer at the University of Oregon, in Scientific American.

The new findings could help scientists better understand how glaciers respond to global warming and how such glacial melt contributes to sea level rise and impacts local ecosystems.

Researchers studying LeConte Glacier in Alaska have found that its melt rate was 10 to 100 times larger than expected. Credit: US Forest Service, Carey Case

Other noteworthy stories

The EGU story

In July we are advertised another vacancy at the EGU Executive Office in Munich, Germany: EGU Communications Officer. The successful candidate will manage the EGU blogs and social media channels and be the office contact point for early career scientists.

Additionally, we are providing an EGU member with the opportunity to visit Brussels and work alongside a Member of the European Parliament (MEP) for a day. The pairing scheme will enable the selected EGU member to experience the daily work of an MEP, learn more about the role of science in policymaking, and potentially provide expertise on a science-policy issue. Interested EGU members should apply by 6 September.

Also in July, we have opened the call for candidates for EGU Union President, General Secretary and Division Presidents: if you’d like to nominate yourself or propose a candidate, you can do so by 15 September.

Finally, if you’d like to apply for financial support from the EGU to organise a meeting, make sure to submit an application by 15 August. This is also the deadline to submit proposals for Union Symposia and Great Debates at the EGU General Assembly 2020. The deadline for scientific sessions and short courses is 5 September.

Imaggeo on Mondays: At the edge of a wildfire

Imaggeo on Mondays: At the edge of a wildfire

The Carpenter 1 fire burned approximately 11,000 ha in the Spring Mountain National Recreation Area (Humboldt-Toiyabe National Forest) near Las Vegas, Nevada between July 1, 2013 and its containment on August 18, 2013. The left side of the photo shows the fire affected arid desert scrub ecosystems at 1500 m (foreground) to subalpine pine ecosystems at 3400 m (background). The foreground of the photo clearly shows the lower-elevation boundary of the burned area, where low-severity fire burned off brush vegetation and Joshua trees.

Description by Teamrat Ghezzehei, as it first appeared on imaggeo.egu.eu.

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/.

Geosciences Column: How erupting African volcanoes impact the Amazon’s atmosphere

Geosciences Column: How erupting African volcanoes impact the Amazon’s atmosphere

When volcanoes erupt, they can release into the atmosphere a number of different gases initially stored in their magma, such as carbon dioxide, hydrogen sulfide, and sulfur dioxide. These kinds of gases can have a big influence on Earth’s atmosphere, even at distances hundreds to thousands of kilometres away.

A team of researchers have found evidence that sulfur emissions from volcanic eruptions in Africa can be observed as far as South America, even creating an impact on the Amazon rainforest’s atmosphere. The results of their study were published last year in the EGU journal Atmospheric Chemistry and Physics.

Amazon Tall Tower Observatory based in the Amazon rainforest of Brazil (Credit: Jsaturno via Wikimedia Commons)

In September 2014, the Amazon rainforest’s atmosphere experienced an unusually sharp spike in the concentration of sulfate aerosols. During this period, the Amazon Tall Tower Observatory (ATTO) based in Brazil reported levels of sulfate never recorded before in the Amazon Basin.

Sulfate aerosols are particles that take form naturally from sulfur dioxide compounds in the atmosphere. When sulfate aerosols spread throughout the atmosphere, the particles often get in the way of the sun’s rays, reflecting the sunlight’s energy back to space. These aerosols can also help clouds take shape. Through these processes, the particles can create a cooling effect on Earth’s climate. Sulfate aerosols can also facilitate chemical reactions that degrade Earth’s ozone layer.

Fossil fuel and biomass burning have been known cause an increase in atmospheric sulfate, but researchers involved in the study found that neither human activity increased the level of sulfate in the atmosphere significantly. Instead, they examined whether a volcanic eruption could be responsible.

Scientists have suggested for some time that sulfur emissions in the Amazon could come from African volcanoes, but until now they’ve lacked proof to properly justify this idea.

Edited Landsat 8 image of the volcanoes Nyamuragira and Nyiragongo in Congo near the city of Goma. (Credit: Stuart Rankin via flickr, NASA Earth Observatory images by Jesse Allen, using Landsat data from the U.S. Geological Survey.

However, in this study the research team involved caught volcanic pair in the act. By analysing satellite images and aerosol measurements, the researchers found evidence that in 2014, emissions from the neighboring Nyiragongo-Nyamuragira volcano complex in the Democratic Republic of the Congo, central Africa, increased the level of sulfate particles in the Amazon rainforest’s atmosphere.

Satellite observations revealed that volcanoes experienced two explosive events in September 2014, releasing sulfur emissions into the atmosphere. During that year, the volcanic complex was reportedly subject to frequent eruptive events, sending on average 14,400 tonnes of sulfur dioxide into the atmosphere a day during such occasions. This amount of gas would weigh more than London’s supertall Shard skyscraper.

Map of SO2 plumes with VCD > 2.5 × 1014 molecules cm−2 color-coded by date of observation. The 15-day forward trajectories started at 4 km (above mean sea level, a.m.s.l.) at four locations within the plume detected on 13 September 2014 (light blue) are indicated by black lines with markers at 24 h intervals. (Credit: Jorge Saturno et al.)

The images further show that these emissions were transported across the South Atlantic Ocean to South America. The sulfate particles created from the emissions were then eventually picked up by an airborne atmospheric survey campaign and the ATTO in the Amazon.

The researchers of the study suggest that these observations indicate that African volcanoes can have an effect on the Amazon Basin’s atmosphere, though more research is needed to understand the full extent of this impact.

By Olivia Trani, EGU Communications Officer

References and further reading

Volcanic gases can be harmful to health, vegetation and infrastructure. Volcano Hazards Program. USGS.

Aerosols and Incoming Sunlight (Direct Effects). NASA Earth Observatory

Saturno, J., Ditas, F., Penning de Vries, M., Holanda, B. A., Pöhlker, M. L., Carbone, S., Walter, D., Bobrowski, N., Brito, J., Chi, X., Gutmann, A., Hrabe de Angelis, I., Machado, L. A. T., Moran-Zuloaga, D., Rüdiger, J., Schneider, J., Schulz, C., Wang, Q., Wendisch, M., Artaxo, P., Wagner, T., Pöschl, U., Andreae, M. O. and Pöhlker, C.: African volcanic emissions influencing atmospheric aerosols over the Amazon rain forest, Atmospheric Chemistry and Physics, 18(14), 10391–10405, doi:10.5194/acp-18-10391-2018, 2018.

Imaggeo on Mondays: Recreating monster waves in art and science

Imaggeo on Mondays: Recreating monster waves in art and science

Featured in this blog post is a collection of images that gives a picture-perfect example of life imitating art.

The photos in the left column are three consecutive still frames of a breaking wave that scientists generated in a lab environment at the University of Edinburgh in the UK. The pictures in the centre and right columns show the same wave images, but now superimposed with the famous 19th century Japanese woodblock print, The Great Wave off Kanagawa.

While the images were produced on opposite sides of the Earth with a few hundreds of years between their creation, the curves and edges of the waves are very similarly positioned.

“Completely coincidentally, in a strange twist of fate, the wave we created bears striking resemblance to The Great Wave off Kanagawa, painted many years ago by the Japanese artist Katsushika Hokusai,” said Mark McAllister, a researcher at the University of Oxford in the UK. He is part of a team of scientists working to better understand the dynamics of freak waves – waves that are unexpectedly large in comparison to the waves that surround it.

The images also highlight the similarities between artists and scientists that often are overlooked: while art and science are different in many ways, both involve observing and trying to interpret their surroundings. The wave simulation photos and the woodblock print both visualise a common endeavor: recreating nature to better understand it.

Simulating monster waves

The photographs in the left column feature the recreation of a very particular wave that took form in 1995 in the North Sea, known as the Draupner freak wave. This particular surface wave was one of the first confirmed observations of a freak wave at sea. The Draupner Oil Platform had taken measurements of the event, reporting that the wave was 26 metres tall (more than twice as tall as the surrounding waves). Rogue waves as high as 30 metres had been reported by sailors and scientists for many years, but until the 20th century there was wide disbelief from the scientific community that such waves were more than myth.

“The measurement of the Draupner wave in 1995 was a seminal observation initiating many years of research into the physics of freak waves and shifting their standing from mere folklore to a credible real-world phenomenon,” said McAllister in a recent press release.

Such rogue waves are capable of causing heavy damage to large ships, and by recreating the Draupner freak wave, McAllister and his colleagues are trying to better understand how this marine phenomenon occurs.

Experiments were carried out in the FloWave Ocean Energy Research facility at the University of Edinburgh. The facility has a circular basin equipped with wavemakers around the entire circumference, allowing scientists to generate waves from any direction and recreate complex wave conditions.

The research team was able to simulate this wave on a smaller scale by crossing two different wave groups at a large angle. They found that when the two wave groups hit each other at 120 degrees, this allowed the freak wave to take shape.

Typically, wave breaking in the ocean limits the maximum height of waves. But when waves cross each other at large angles, wave breaking behaviour changes, removing typical height limitations.

Monster wave immortalised in print

The Great Wave off Kanagawa, one of Hokusai’s most famous prints, depicts three crewed boats at sea, seemingly seconds away from crashing into a monstrous wave, with Japan’s Mount Fugi sitting in the distance. The work is often interpreted to symbolize the eternity and formidable force of nature compared to the frailty of humans.

While the print is often considered to be an artistic representation of a tsunami, one study argues that the features and conditions are more similar to a freak wave event. By using the boats and the mountains as reference points, the researchers involved in the study estimate that the great wave is approximately 10-12 metres in height.

While many artists distort reality to enhance and highlight certain aspects of their work, the researchers point out that Hokusai’s work is likely to be representative of nature, noting that he strove for years to understand the structure of his surroundings and draw them accurately in his art. In the afterward of his 1834 collection of prints containing The Great Wave of Kanagawa, Hokusai writes:

“Since the age of six, I had a habit of sketching from life. From fifty onwards I began producing a fair amount of art work, but nothing I did before the age of seventy was worthy of attention. At seventy-three, I began to grasp the structures of birds and beasts, insects and fish, and of the way plants grow.

If only I go on trying, I will surely understand them still better by the time I am eighty, so that by ninety I will have penetrated to their essential nature. At one hundred, I hope I may have a divine understanding of them, while at one hundred and ten I may have reached the stage where every dot and every stroke I paint will be alive. May men of great age and virtue see that I am not hoping for too much!”

By Olivia Trani, EGU Communications Officer

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/.