GeoLog
Olivia Trani

Olivia Trani

Olivia Trani is the Communications Officer at the European Geosciences Union. She is responsible for the management of the Union's social media presence and the EGU blogs, where she writes regularly for the EGU's official blog, GeoLog. She is also the point of contact for early career scientists (ECS) at the EGU Office. Olivia has a MS in Science Journalism from Boston University and her work has appeared on WBUR-FM, Inside Science News Service, and the American Geophysical Union. Olivia tweets at @oliviatrani.

Imaggeo on Mondays: The ancient guard of Altai

Imaggeo on Mondays: The ancient guard of Altai

In the heart of Eurasia, an ancient stone statue overlooks the expanse of the Kurai Valley and the Altai Mountains in Russia. This relic was crafted more than a thousand years ago, sometime during the 6th or 7th century. A Turkish clan that inhabited the region, known as the First Turkic Khaganat, would often erect stones as monuments of funeral rituals.

Natalia Rudaya, who took this photograph, is a senior researcher at the Institute of Archeology and Ethnography of the Siberian Branch of the Russian Academy of Sciences. She and her research team were taking sediment cores from the bottom of Lake Teletskoye, the largest lake in the Altai Mountains, in southeastern West Siberia, close to the photograph’s location.

The lake samples give clues on how the local environment has shifted over the last couple thousand years, and how these changes might have influenced the human societies that inhabited the Altai Mountains. Investigating palaeoclimates and past vegetation shifts are also important for understanding how current climate change will affect Earth’s ecosystems.

By analysing sediment cores, Rudaya and her colleagues were able to reconstruct the region’s environmental and climatic history. Their results showed that in the beginning of the mid- to late- Holocene (roughly 4,250 years ago), the region exhibited a relatively cool and dry climate, and the land surface was dominated by Siberian pine and Siberian fir forests. However, starting around 3,900 years ago, plant populations faced significant deforestation for roughly three centuries. Then 3,600 years ago, dark coniferous mountain taiga began to extend across the territory; the sediment samples also show that this forest expansion coincided with slight increases in temperature and humidity. This climate persisted for roughly 2,000 years, then the mountainous environment faced cooler temperatures once again.

References

Rudaya, N. et al.: Quantitative reconstructions of mid- to late holocene climate and vegetation in the north-eastern altai mountains recorded in lake teletskoye, Global and Planetary Change., 141, 12-24, 2016

Huang, X. et al.: Holocene Vegetation and Climate Dynamics in the Altai Mountains and Surrounding Areas, Geophysical Research Letters, 45, 6628-6636, 2018.

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/.

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, 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 south Indian state of Kerala has suffered unusually heavy monsoon rainfall this month, triggering the worst flooding the state has seen in more than a century.

Officials have reported nearly 500 deaths, while more than one million people have been evacuated to over 4,000 relief camps.

Between 1 and 19 August, the region received 758.6 milimetres of rain, 2.6 times the average for that season. In just two days (15-16 August), Kerala sustained around 270 milimetres of rainfall, the same amount of rainfall that the entire state receives in one month typically, said Roxy Mathew Koll, a climate scientist at the Indian Institute of Tropical Meteorology and the National Oceanic and Atmospheric Administration, to BBC News.

Due to the heavy downpours, rivers have overflowed, water from several dams has been released, and lethal landslides have swept away rural villages.

“Officials estimated about 6,000 miles (10,000km) of roads had been submerged or buried by landslides,” reported the Guardian. “Communications networks were also faltering, officials said, making rescue efforts harder to coordinate.”

Experts report that the event’s severity stems from many factors coming together.

For instance, a recent study led by Koll has shown that in the past 50-60 years, monsoon winds have weakened, delivering less rain on average in India. However, the distribution of rainfall is uneven, with long dry spells punctuated by heavy rainfall events. Koll’s research suggests that central India has experienced a threefold rise in the number of widespread extreme rain events during 1950-2012. In short, it doesn’t rain as often; but when it rains, it pours.

Scientists also say that increased development in the region had exacerbated the monsoon’s impact.

For example, usually when storms release heavy rainfall, much of that water is absorbed or slowed down by vegetation, soil, and other natural obstacles. However, scientists point out that “over the past 40 years Kerala has lost nearly half its forest cover, an area of 9,000 km², just under the size of Greater London, while the state’s urban areas keep growing. This means that less rainfall is being intercepted, and more water is rapidly running into overflowing streams and rivers.”

To make matters worse, increased development can also change how effectively rivers handle heavy downpours. For instance, canals and bridges can make rivers more narrow and can create sediment build-up, which slows water flow. “When there is a sudden downpour, there is not enough space for the water so it floods the surrounding area,” explains Nature.

Some experts have added that badly-timed water management practices are also partly to blame for the flood’s devastation on local communities.

“A contributing factor is that after the heavy rain, authorities began to release water from several of the state’s 44 dams, where reservoirs were close to overflowing. The neighbouring state of Tamil Nadu also purged water from its over-filled Mullaperiyar dam, which wreaked yet more havoc downstream in Kerala,” Nature adds.

While floodwaters began to recede in late August, rescue teams are still searching submerged neighborhoods to deliver aid and evacuate survivors.

What you might have missed

Water on moon confirmed

Recent research published this month suggest that there is almost certainly frozen water on the moon’s surface.

The image shows the distribution of surface ice at the Moon’s south pole (left) and north pole (right). Blue represents the ice locations, plotted over an image of the lunar surface, where the gray scale corresponds to surface temperature (darker representing colder areas and lighter shades indicating warmer zones). (Credit: NASA)

“Previous observations indirectly found possible signs of surface ice at the lunar south pole, but these could have been explained by other phenomena, such as unusually reflective lunar soil,” NASA officials said in a published statement.

Now, scientists involved with the new study claim that they’ve found definitive evidence that ice is located within craters on the moon’s north and south poles.

During daylight hours, the moon’s surface can be brutally hot, often reaching temperatures as high as 100 degrees Celsius. However, due to the moon’s axial tilt, some parts of the lunar poles don’t receive sunlight. Scientists estimate that some craters situated within these permanently dark polar regions are cold enough to sustain pockets of water-ice.

Because the moon’s poles are so dark, scientists have had a hard time studying the lunar craters. But Shuai Li, a planetary researcher at the University of Hawaii at Manoa and lead author of the study, and his colleagues tried a creative way to shed some light on shadowed craters, using data collected from India’s Chandrayaan-1 lunar probe ten years ago.

“They peered into dark craters using traces of sunlight that had bounced off crater walls,” reports the New York Times. “They analyzed the spectral data to find places where three specific wavelengths of near-infrared light were absorbed, indicating ice water.”

As of now, the researchers still aren’t sure how much ice there is, or how it found its way to the moon’s poles. But if enough accessible ice exists close to the lunar surface, the water could be used as a resource for future missions to the moon, from a source of drinking water to rocket fuel.

Mapping Earth’s winds from above

Also this month, scientists from the European Space Agency launched a satellite that will profile the world’s winds, in hopes that the data will greatly improve weather forecasts and provide insight for long-term climate research. The satellite, named Aeolus after the celestial keeper of the winds in Greek mythology, was sent to orbit from French Guiana on Wednesday 22 August.

The rocket was due to lift off on Tuesday, but the launch was postponed – ironically – due to high altitude winds,” reports BBC News.

Aeolus profiling the word’s winds (Credit: ESA)

Equipped with a Doppler wind lidar, Aeolus will send powerful laser pulses down to Earth’s atmosphere and measure how air molecules and other particles in the wind scatter the light beam.

Researchers expect that wind data from Aeolus will greatly improve current efforts to forecast storms, especially their severity over time. While scientists have many ways to measure wind behavior, current methods are unable to capture wind movement from all corners of the Earth. Aeolus will be the first mission to monitor winds across the entire globe.

Using data collected by Aeolus, experts estimate that the quality of forecasts will increase by up to 15% within the tropics, and 2-4% outside of the tropics.

“If we improve forecasts by 2%, the value for society is many billions of dollars,” said Lars Isaksen, a meteorologist at the European Centre for Medium-Range Weather Forecasts (ECMWF), to Nature.


Learn how Earth’s wind is generated and why we need to measure it. (Credit: ESA

Links we liked

The EGU story

Do you enjoy the EGU’s annual General Assembly but wish you could play a more active role in shaping the scientific programme? Now is your chance! Help shape the scientific programme of the 2019 General Assembly.

Before the end of today (6 September), you can suggest:

This month we released two press releases from research published in our open access journals. Take a look at them below:

Landslides triggered by human activity on the rise

More than 50,000 people were killed by landslides around the world between 2004 and 2016, according to a new study by researchers at UK’s Sheffield University. The team, who compiled data on over 4800 fatal landslides during the 13-year period, also revealed for the first time that landslides resulting from human activity have increased over time. The research is published today in the European Geosciences Union journal Natural Hazards and Earth System Sciences.

Deadline for climate action – Act strongly before 2035 to keep warming below 2°C

If governments don’t act decisively by 2035 to fight climate change, humanity could cross a point of no return after which limiting global warming below 2°C in 2100 will be unlikely, according to a new study by scientists in the UK and the Netherlands. The research also shows the deadline to limit warming to 1.5°C has already passed, unless radical climate action is taken. The study is published today in the European Geosciences Union journal Earth System Dynamics.

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.

Imaggeo on Mondays: Antarctic winds make honeycomb ice

Imaggeo on Mondays: Antarctic winds make honeycomb ice

These delicate ice structures may look like frozen honeycombs from another world, but the crystalline patterns can be found 80 degrees south, in Antarctica, where they are shaped by the white continent’s windy conditions.

In Western Antarctica is a 9-kilometre line of rocky ridges, called Patriot Hills. Often cold wind furiously descends from the hills across Horseshoe Valley glacier, sculpting doily-like designs into the surface layer. “The wind exploits weaknesses in the ice structure, picking out the boundaries between individual ice crystals, leading to the formation of a honeycomb pattern,” said Helen Millman, a PhD student at the University of New South Wales Climate Change Research Centre, who captured this photograph at Patriot Hills.

Besides creating decorations out of Antarctica’s ice, the region’s intense winds, known as katabatic winds, also cause sublimation, in which the ice on the glacier’s surface turns directly into water vapour. This phenomenon creates a snow-free zone that experiences a net loss in frozen mass, also known as ablation; it also gives the ice a slightly blue hue and ”small, smooth waves that resemble the ocean in a light breeze, despite the intensity of the katabatic winds,” Millman added.

A stretch of blue ice in Antarctica. Credit: Helen Millman

“Since older ice rises as the surface layers are ablated, the ice at the surface of blue ice areas may be hundreds of thousands, or even millions of years old,” said Millman. This allows for some pretty interesting geological artifacts to reach the glacier’s surface, such as meteorites. “This conveyor belt of old ice rising to the surface means that high concentrations of meteorites can be found in blue ice areas.” Scientists can study these ancient Antarctic meteorites to learn more about the formation and evolution of our solar system. The Antarctic Search for Meteorites program for instance has collected more than 21,000 meteorites since 1976, and are on the hunt for more.

References

IceCube South Pole Neutrino Obesrvatory, University of Wisconsin-Madison

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: Fairy chimneys in Love Valley

Imaggeo on Mondays: Fairy chimneys in Love Valley

Every year tourists from around the world flock to Love Valley in Göreme National Park in the Cappadocia region of central Turkey to marvel at the region’s peculiarly pointy geological features. These cone-shaped formations, known as ‘fairy chimneys’ or hoodoos, dominate the park’s skyline, with some rocky spires extending up to 40 metres towards the sky.

While the name ‘fairy chimney’ suggests mythical origins, these rocks began to take shape millions of years ago, when many active volcanoes dominated the region. “The deposits of [volcanic] ash, lava and basalt laid the foundations for today’s landscape,’ commented Alessandro Demarchi in the photo’s description, who captured the stunning photograph featured today. The volcanic material consolidated into a soft rock known as ‘tuff.’ Then over the years, natural weathering forces like wind and water eroded weaker parts of the rock away, leaving behind the pinnacles we see now.

Around the 4th century, during the reign of the Roman empire, many Christian pilgrims traveled to Cappodocia to flee persecution. They built their new life into the region’s rocks, carving out a network of homes and churches from the towers of tuff. If you look closely at background of the image, you can even spot remnants of their handiwork.

The region was named a UNESCO World Heritage Site in 1985, and today you can enjoy the extraordinary geological formations, as well as their cultural history, either from the ground or up in the air through hot air balloon tours.

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/.