Scientists Study Ice Shelf by Listening to Its Changing Sounds
By Marlene Cimons
Researchers monitoring vibrations from Antarctica's Ross Ice Shelf were flabbergasted not long ago to hear something unexpected—the ice was "singing" to them. "We were stunned by a rich variety of time-varying tones that make up this newly described sort of signal," said Rick Aster, professor of geosciences at Colorado State University, one of the scientists involved in the study.
Researchers set out to study low-frequency vibrations that arose from earthquakes and ocean waves. They were surprised to hear the ice sheet "singing" after examining the higher frequencies. The sound, which resembled a low moan, turned out to be a valuable tool. "The tones in these signals shift when the surface of the ice shelf is disturbed by changes in surface dunes or near-surface melt," Aster said.
Changes in the ice shelf's seismic hum could alert scientists when "melt ponds" or cracks appear in the ice, indicating that the ice may become vulnerable to breaking off—a mounting concern as climate change fuels extensive melting. Ice shelves all over Antarctica are becoming thinner, and some have collapsed or retreated due to rising ocean and air temperatures. In the past, these shelves have sometimes collapsed suddenly, without notice.
Climate scientists are concerned about ice shelves on the edge of Antarctica because they hold back large inland glaciers, "like a cork in a bottle," Aster said. Those glaciers then melt into the ocean, raising sea levels. Scientists watched that happen after the Larsen B ice shelf collapsed in 2002—glaciers behind the ice sheet began to thin. All told, Antarctica is home to roughly 7 million cubic miles of ice which, if it melted, would raise sea levels around 200 feet.
When ice shelves disintegrate, glaciers move out to sea. Ted Scambos & Michon Scott, National Snow and Ice Data Center
Melting ice doesn't just add water to the sea. It also changes how that water is distributed. That's because the Antarctic ice sheet exerts a gravitational pull over surrounding waters. "The ice sheet is so massive that it attracts a bulge of ocean close to the continent," Aster said. "When the icecap melts, this bulge relaxes and sea level goes up on the other side of the planet." This produces more coastal flooding in the northern hemisphere.
Researchers studied the Ross Ice Shelf, a Texas-sized plate of ice that floats atop the Southern Ocean. The Ross Ice Shelf—Antarctica's largest ice shelf—is covered in thick blankets of snow, often several meters deep, that are topped with massive snow dunes, like sand dunes in a desert. This snow layer insulates the underlying ice from heating when temperatures rise.
Rick Aster, professor of geosciences at Colorado State UniversityRick Aster
The newly discovered noises are the result of winds blowing across snow dunes on the Rise Ice Shelf. This causes the ice surface to vibrate, producing near-constant seismic "tones" that researchers can use to monitor melting and other changes from afar. The study appears in Geophysical Research Letters, a journal of the American Geophysical Union.
Scientists currently use a variety of methods to monitor an ice shelf—analyzing snow pits, for example, or gathering satellite data. According to Aster, "we may eventually be able to model critical elements of its structure using seismology alone," meaning scientists could track the melt of the ice sheet by listening to its song, using other tools to confirm what they found.
The Ross Ice Shelf. SourceJosh Landis
"We can also see the rearrangement of drifted snow, that is, dunes at the surface, or instances where new snow is deposited or blown away," he added. "This tool provides site-specific information about the ice shelf that can be monitored continuously, which is something you can't do digging snow pits."
The researchers buried 34 extremely sensitive seismic sensors under the snow across the ice shelf for two years, from late 2014 to early 2017, which allowed them to monitor its vibrations, structure and movements. They discovered that the shelf nearly continuously sings at frequencies of five or more cycles per second, stimulated by winds that blow across its dune‐like landscape.
Researchers studying the Ross Ice ShelfRick Aster
They also found changes in frequency whenever storms whipped up the snow dunes, or when the air got warmer or colder. "It's kind of like you're blowing a flute, constantly, on the ice shelf," said Julien Chaput, a geophysicist and mathematician at Colorado State University and lead author of the study. "Either you change the velocity of the snow by heating or cooling it, or you change where you blow on the flute, by adding or destroying dunes. And that's essentially the two forcing effects we can observe."
As the ice shelf changes its tune, "we can track extremely sensitive details about it," Chaput added. "Basically, what we have on our hands is a tool to monitor the environment and its impact on the ice shelf."
Antarctica Lost a London-Sized Area of Underwater Ice in Only 6 Years https://t.co/WSN8jMovLO @AntarcticaNews… https://t.co/tIUnQLKnFY— EcoWatch (@EcoWatch)1522867167.0
Reposted with permission from our media associate Nexus Media.
EcoWatch Daily Newsletter
The shelter in place orders that brought clean skies to some of the world's most polluted cities and saw greenhouse gas emissions plummet were just a temporary relief that provided an illusory benefit to the long-term consequences of the climate crisis. According to new research, the COVID-19 lockdowns will have a "neglible" impact on global warming, as Newshub in New Zealand reported.
- Coronavirus Lockdown Linked to Falling Air Pollution Levels in Italy ... ›
- Greenhouse Gas Emissions Set for Record Decline Due to ... ›
- Coronavirus Lockdowns Led to Record 17% Emissions Drop ... ›
- India's Air Pollution Plummets in COVID-19 Lockdown - EcoWatch ›
Scientists have discovered and diagnosed the first instance of malignant cancer in a dinosaur, and they did so by using modern medical techniques. They published their results earlier this week in The Lancet Oncology.
- New Blood Test Can Detect Cancer 4 Years Before Symptoms ... ›
- Skull of Smallest Known Dinosaur Found in 99-Million-Year Old Amber ›
- Antarctica Was a Rainforest During the Times of Dinosaurs, New ... ›
- Earth Is Hurtling Towards a Catastrophe Worse Than the Dinosaur ... ›
- Help Save the World's Last Dinosaur - EcoWatch ›
By Joe Roman and Taylor Ricketts
The COVID-19 pandemic in the United States is the deepest and longest period of malaise in a dozen years. Our colleagues at the University of Vermont have concluded this by analyzing posts on Twitter. The Vermont Complex Systems Center studies 50 million tweets a day, scoring the "happiness" of people's words to monitor the national mood. That mood today is at its lowest point since 2008 when they started this project.
The Hedonometer measures happiness through analysis of key words on Twitter, which is now used by one in five Americans. This chart covers 18 months from early 2019 to July 2020, showing major dips in 2020. hedonometer.org<p>These same tweets also indicate a potential salve. Before pandemic lockdowns began, doctoral student <a href="https://scholar.google.com/citations?user=0P0ZYbIAAAAJ&hl=en" target="_blank">Aaron Schwartz</a> <a href="https://doi.org/10.1002/pan3.10045" target="_blank">compared tweets before, during, and after visits to 150 parks, playgrounds and plazas</a> in San Francisco. He found that park visits corresponded with a spike in happiness, followed by an afterglow lasting up to four hours.</p><p>Tweets from parks contained fewer negative words such as "no," "not" and "can't," and fewer first-person pronouns like "I" and "me." It seems that nature makes people more positive and less self-obsessed.</p><p>Parks keep people happy in times of global crisis, economic shutdown and public anger. Research has also shown that transmission rates for COVID-19 are <a href="https://www.sfchronicle.com/news/article/Is-risk-of-coronavirus-transmission-lower-15287602.php" target="_blank">much lower outdoors than inside</a>. As scholars who study <a href="https://scholar.google.com/citations?user=yFzb2EUAAAAJ&hl=en" target="_blank">conservation</a> and how nature <a href="https://scholar.google.com/citations?user=CCnUeN8AAAAJ&hl=en" target="_blank">contributes to human well-being</a>, we see opening up parks and creating new ones as a straightforward remedy for Americans' current blues.</p>
Park Visits Are Up During the Pandemic<p>According to the Hedonometer, sentiments expressed online started trending lower in mid-March as the impacts of the pandemic became clear. As lockdowns continued, they registered the lowest sentiment scores on record. Then in late May, effects from George Floyd's death in police custody and the following protests and police response once again could be seen on Twitter. May 31, 2020 was the saddest day of the project.</p><p>Recent surveys of park visitors around the University of Vermont have shown people <a href="https://osf.io/preprints/socarxiv/sd3h6" target="_blank">using green spaces more</a> since COVID-19 lockdowns began. Many people reported that parks were highly important to their well-being during the pandemic.</p>
<div id="4c7e4" class="rm-shortcode" data-rm-shortcode-id="bc0ac146ab2a94228f32d973fc2ab272"><blockquote class="twitter-tweet twitter-custom-tweet" data-twitter-tweet-id="1289428912879964160" data-partner="rebelmouse"><div style="margin:1em 0">#Goldengatepark #sf #quarantinemood https://t.co/9l3ufnbkt6</div> — Suvd (@Suvd)<a href="https://twitter.com/Suvd19486406/statuses/1289428912879964160">1596258783.0</a></blockquote></div><p>The powerful effects of nature are strongest in large parks with more trees, but smaller neighborhood parks also provide a significant boost. Their impact on happiness is real, measurable and lasting.</p><p>Twitter records show that parks increase happiness to a level similar to the bounce at Christmas, which typically is the happiest day of the year. Schwartz has since expanded his <a href="https://arxiv.org/pdf/2006.10658.pdf" target="_blank">Twitter study</a> to the 25 largest cities in the U.S. and found this bounce everywhere.</p><p>Parks and public spaces won't cure COVID-19 or stop police brutality, but they are far more than playgrounds. There is growing evidence that parks contribute to mental and physical health in a range of communities.</p><p>In a 2015 study, for example, Stanford researchers sent people out for one of two walks: through a local park or on a busy street. Those who walked in nature showed <a href="https://doi.org/10.1016/j.landurbplan.2015.02.005" target="_blank">improved moods and better memory performance</a> compared to the urban group. And a team led by <a href="https://penniur.upenn.edu/people/eugenia-gina-south" target="_blank">Gina South</a> of the University of Pennsylvania showed in a 2018 study that greening and cleaning up blighted vacant lots in Philadelphia <a href="http://dx.doi.org/10.1001/jamanetworkopen.2018.0298" target="_blank">reduced local residents' feelings of depression, worthlessness and poor mental health</a>.</p>
Creative Strategies<p>It isn't easy to create new parks on the scale of San Francisco's Golden Gate Park or the Washington Mall, but smaller projects can expand outdoor space. Options include greening vacant lots, closing streets and investing in existing parks to make them safer, greener and shadier and support wildlife.</p><p>These initiatives don't have to be capital-intensive. In the University of Pennsylvania study, for example, renovating a vacant lot by removing trash, planting grass and trees and installing a low fence cost only about US$1,600.</p><p>Urban green space is most needed in neighborhoods that have lacked funding for parks, especially given <a href="https://www.nytimes.com/2020/04/08/nyregion/coronavirus-race-deaths.html" target="_blank">COVID-19's disproportionate impact on Black and Latinx people</a>.</p><p>Cities can also create parklike spaces by <a href="https://theconversation.com/with-fewer-cars-on-us-streets-now-is-the-time-to-reinvent-roadways-and-how-we-use-them-140408" target="_blank">closing streets to cars</a>. Many cities worldwide are currently retooling their transportation systems for the post-COVID-19 world in order to <a href="https://thecityfix.com/blog/bicycles-slower-speeds-livable-city-paris-mayor-anne-hidalgo-plans-ambitious-second-term-dario-hidalgo/" target="_blank">reallocate public space</a>, widen sidewalks and make more space for nature.</p><p>Urban designers, artists, ecologists and other citizens can play a direct role, too, creating pop-up parks and green spaces. Some advocates <a href="https://www.bloomberg.com/news/articles/2017-09-15/a-brief-history-of-park-ing-day" target="_blank">transform parking spaces into mini-parks</a> with grass, potted trees and seating for just the time on the meter, to make a larger point about turning so much public space over to cars.</p><p>Or cities can invest a little more. Minneapolis, Cincinnati and Arlington, Virginia, have won <a href="https://www.tpl.org/parkscore" target="_blank">national recognition</a> for their ambitious investments in public park systems. These areas could serve as models for neighborhoods that lack access to parks.</p>
<div id="25fd0" class="rm-shortcode" data-rm-shortcode-id="383f0d2df0237e9359c30dcce6cd6c42"><blockquote class="twitter-tweet twitter-custom-tweet" data-twitter-tweet-id="1276558744835379201" data-partner="rebelmouse"><div style="margin:1em 0">Looking to safely get outside? Check out the best parks for social distancing in this year's top ten ParkScore citi… https://t.co/HJjEtDsrTD</div> — The Trust for Public Land (@The Trust for Public Land)<a href="https://twitter.com/tpl_org/statuses/1276558744835379201">1593190296.0</a></blockquote></div>
A New Park Deal?<p>The United States has historically driven economic recovery with major infrastructure investments, like the New Deal in the 1930s and the 2009 <a href="https://www.investopedia.com/terms/a/american-recovery-and-reinvestment-act.asp" target="_blank">American Reinvestment and Recovery Act</a>. Such investments could easily include nature-positive spaces.</p><p>Parks are not panaceas, as evidenced by the widely publicized <a href="https://www.nytimes.com/2020/07/06/nyregion/amy-cooper-false-report-charge.html" target="_blank">racist confrontation between a white woman and a Black birder</a> in New York's Central Park in early July. But Hedonometer data add to a <a href="https://advances.sciencemag.org/content/5/7/eaax0903?utm_source=miragenews&utm_medium=miragenews&utm_campaign=news" target="_blank">growing body of evidence</a> that they provide <a href="https://doi.org/10.1073/pnas.1807504116" target="_blank">clear mental health benefits</a>. Creating and expanding parks also <a href="https://www.nrpa.org/contentassets/f568e0ca499743a08148e3593c860fc5/economic-impact-study-summary.pdf" target="_blank">generates jobs and economic activity</a>, with much of the money spent locally.</p><p>We believe investments in nature are well worth it, offering both short-term solace in difficult times and long-term benefits to health, economies and communities.</p>
- Growing Up Near Nature Is Good for Your Adult Mental Health, New ... ›
- Doctors Prescribe Spending Time In Parks - EcoWatch ›
- This Is the Best Type of Green Space for Your Mental Health ... ›
New York State Attorney General Letitia James announced Thursday that she will attempt to dismantle the National Rifle Association (NRA), arguing that years of corruption and mismanagement warrant the dissolution of the activist organization, as CNN reported.
<div id="7eb49" class="rm-shortcode" data-rm-shortcode-id="83819841e380a7072ec66d3186c160e8"><blockquote class="twitter-tweet twitter-custom-tweet" data-twitter-tweet-id="1291705003984510977" data-partner="rebelmouse"><div style="margin:1em 0">🚨RESPONSE to #Mauritius #OILSpill 🚨 “Once again we see the risks in oil: aggravating the #ClimateCrisis, as well as… https://t.co/PBLioZat6X</div> — Greenpeace Africa (@Greenpeace Africa)<a href="https://twitter.com/Greenpeaceafric/statuses/1291705003984510977">1596801446.0</a></blockquote></div><p>"There is no guaranteed safe way to extract, transport and store fossil fuel products. This oil leak is not a twist of fate, but the choice of our twisted addiction to fossil fuels. We must react by accelerating our withdrawal from fossil fuels," Greenpeace Africa Senior Climate and Energy Campaign Manager Happy Khambule said in a <a href="https://www.greenpeace.org/africa/en/press/11864/greenpeace-africa-response-to-mauritius-oil-spill/?utm_campaign=oil&utm_source=t.co&utm_medium=post&utm_content=single-image&utm_term=mauritius-oil-spill-reactive" target="_blank">statement Friday</a>. "Once again we see the risks in oil: aggravating the <a href="https://www.ecowatch.com/tag/climate-crisis" target="_self">climate crisis</a>, as well as devastating oceans and <a href="https://www.ecowatch.com/tag/biodiversity" target="_self">biodiversity</a> and threatening local livelihoods around some of Africa's most precious lagoons."</p>
- Which Country Will Be First to Go Completely Underwater Due to ... ›
- Overfishing Starts Here - EcoWatch ›
By Gianna-Carina Grün
While the first countries are easing their lockdowns, others are reporting more and more new cases every day. Data for the global picture shows the pandemic is far from over. DW has the latest statistics.
What's the Current Global Trend?<p>The goal for all countries is to make it to the blue part of the chart and stay there. Countries and territories in this section reported zero new cases both this week (past seven days) and the week before.</p><p>Currently, that is the case for 14 out of 209 countries and territories. </p>
How Has the Covid-19 Trend Evolved Over the Past Weeks?<p>The situation has improved slightly: 87 countries report more cases this week than last week. </p>
- Coronavirus Has Infected More Than 60,000 Worldwide, New ... ›
- Apple Fire Forces 7,800 to Seek Shelter in Coronavirus-Ravaged ... ›
- CDC Expands List of Those With Higher COVID-19 Risks - EcoWatch ›
- The South Isn't Prepared for a COVID-19 Surge - EcoWatch ›
- Until Teachers Feel Safe, Widespread In-Person K-12 Schooling ... ›
- Teens and Tweens Are Fastest COVID-19 Spreaders, New Study ... ›
- How Other Countries Reopened Schools During the Pandemic ... ›
- Young Children May Have Higher Coronavirus Levels, Raising ... ›
- COVID-19: What Experts Think About Reopening Schools - EcoWatch ›