How Underwater Microphones Are Helping Scientists Measure Climate Change
By Kristen Pope
Melting and crumbling glaciers are largely responsible for rising sea levels, so learning more about how glaciers shrink is vital to those who hope to save coastal cities and preserve wildlife.
But it is hard to get good pictures and measurements because glaciers typically are in remote, difficult-to-reach, and even dangerous locations. Satellites are often used to measure glacial retreat, but these images are far from complete, especially when it's cloudy, foggy, raining, or snowing.
So researchers have turned to hydrophones, instruments that use underwater microphones to gather data beyond the reach of any camera or satellite. Hydrophones can record underwater in all conditions. Originally used by the military to detect submarines, hydrophones are now one more tool scientists have to learn about climate change. The devices collect data continuously and they are relatively inexpensive and easy to deploy and maintain in many different areas of the world to monitor sea ice, underwater earthquakes, ship noise, and even wildlife patterns.
Groans, Creaks, Icebergs’ Calving Splashes
Oskar Glowacki already knew that melting glacial ice sounds like frying bacon. As ice bubbles burst, anyone nearby can hear crackling and popping, said Glowacki, a postdoctoral scholar at the Scripps Institution of Oceanography. Using hydrophones, he and other scientists now can make more nuanced measurements of how a changing climate sounds underwater, from the groans, creaks and splashes of a calving iceberg to the changes in whale songs as the ocean warms.
Glowacki recently used a pair of hydrophones to study the underwater world of glaciers, publishing his findings in The Cryosphere. He and co-author Grant B. Deane measured glacier retreat by recording the sounds of ice – from small chunks to enormous slabs – falling off the glacier and splashing into the water.
During the summer of 2016, Glowacki's team placed two hydrophones near Hansbreen Glacier in Hornsund Fjord, Svalbard. For a month and a half, they recorded sounds, also using three time-lapse cameras to collect images – including the "drop height" (how far the ice fell into the water) – so they could compare photos to the recordings. The team created a formula to represent the relationship between the size of a piece of ice falling from a glacier and the sound it makes underwater, also accounting for the pieces of ice falling from varying heights. (Hear an example of the sound an iceberg makes while calving here.)
"Iceberg calving, defined as mechanical loss of ice from the edges of glaciers and ice shelves, is thought to be one of the most important components of the total ice loss," they note in their paper. They mention also that 32-40% of the Greenland ice sheet's mass loss is from solid ice discharge. However, Glowacki says it isn't just one process leading to glaciers losing mass: Surface melt, calving, and under-sea melting are all contributing factors.
Satellites are often used to measure glacial retreat, but the images they provide don't present a complete picture, and Glowacki and other scientists say they hope hydrophones can help provide more answers. Given that glaciers are typically remote and difficult to reach, collecting data remotely is key. Hydrophones, on the other hand, can record underwater in all these conditions.
Hydrophones also collect acoustic data and smaller events hard to find from a satellite image. "In a single day, [you] can have 100 or 200 icebergs breaking off from a single glacier," Glowacki says.
Glowacki says he and his team plan to further study iceberg calving, including studying additional glaciers, and collecting data for longer periods of time.
Unlocking Information About Antarctic Ice Shelf
Other researchers also are using hydrophones to learn more about crumbling glaciers. Bob Dziak, research oceanographer with the NOAA/Pacific Marine Environmental Laboratory acoustics research group, captured a massive calving event of the Nansen Ice Shelf in Antarctica with a hydrophone. He published the results with colleagues in Frontiers in Earth Science
On April 7, 2016, satellite images showed a massive calving event had occurred on the ice shelf. The paper described it as the "first large scale calving event in >30 years."
However, once Dziak and colleagues delved into the data from three hydrophones deployed 60 kilometers east of the ice shelf, they uncovered a series of "icequakes" from January to early March 2016. He and other researchers believe that much of the ice actually broke free in mid-January to February, but it remained in the same location until an April storm – which their paper described as the "largest low-pressure storm recorded in the previous seven months" – broke the ice free.
"We suspected that the icebergs broke apart but remained in place – kind of pinned in place – until a major storm with high winds passed through the area and, finally, it was that last push that pushed the icebergs out to sea," Dziak says.
He and his co-authors wrote that "fortuitous timing and proximity of the hydrophone deployment presented a rare opportunity to study cryogenic signals and ocean ambient sounds of a large-scale ice shelf calving and iceberg formation event."
Listening to Songs of Humpback Whales
Monterey Bay Aquarium Research Institute studies the ocean, including its acoustics. One of the institute's projects involves examining the soundscape of California's Monterey Bay, including sounds from animals, humans, weather, and geologic processes like earthquakes. The researchers once even recorded an under-sea landslide. They also focus on recording and analyzing the songs of humpback whales. Male humpback whales' songs can be over 15 minutes in length, and they can be repeated for long periods of time – even hours. Listening to these songs and analyzing them can provide unique insights into the lives of these complex animals.
"Any time we want to study marine mammals, sound gives us a window into their lives because they use sound for all of their essential life activities, really," says institute biological oceanographer John Ryan. "Communication, foraging, reproduction, navigation – depending on the species, of course."
Previously, scientists had thought singing occurred only during courtship and mating, but now they think whales may also use song while migrating and hunting. They know song has a crucial role in the whales' lives.
"There's a whole other dimension to humpback whale song," Ryan says. "It is a mode of cultural transmission in this species. They learn songs from each other. They share songs as a population, and when populations mix and mingle, they learn new ideas, they explore with their song, improvise, and it's a real essential part of their culture."
In 2015, institute researchers placed a hydrophone 3,000 feet deep, recording and analyzing humpback whale songs. Between 2015 and 2018, they collected over 26,000 hours of audio, which they used computer software to analyze. The researchers determined "peak singing season" in November through January, and they found most singing occurred at night. During peak season, songs were heard around 70% of the night.
However, from September 2015 to May 2016, they detected whales singing only about 11% of the time. Those months correlated with a period when the water temperature was especially high, depleting stocks of vital food sources like anchovies and krill, and correlating also with a toxic algal bloom. Scientists think the whales may have had to devote more time and energy to finding food, leaving less for singing. As researchers continue to study the worlds' oceans, they will undoubtedly learn more about underwater mysteries.
Listen to MBARI's live stream from beneath the bay here.
Reposted with permission from Yale Climate Connections.
Many people shop online for everything from clothes to appliances. If they do not like the product, they simply return it. But there's an environmental cost to returns.
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EcoWatch Daily Newsletter
By Dolf Gielen and Morgan Bazilian
John Kerry helped bring the world into the Paris climate agreement and expanded America's reputation as a climate leader. That reputation is now in tatters, and President-elect Joe Biden is asking Kerry to rebuild it again – this time as U.S. climate envoy.
Energy Is at the Center of the Climate Challenge<p>The <a href="https://science2017.globalchange.gov/chapter/1/" target="_blank">effects of climate change</a> are already evident across the globe, from <a href="https://theconversation.com/100-degrees-in-siberia-5-ways-the-extreme-arctic-heat-wave-follows-a-disturbing-pattern-141442" target="_blank">extreme heat waves</a> to <a href="https://science2017.globalchange.gov/chapter/12/" target="_blank">sea level rise</a>. But while the challenge is daunting, there is hope. Solar and wind power have become the <a href="https://www.irena.org/publications/2020/Jun/Renewable-Power-Costs-in-2019" target="_blank">cheapest forms of power generation globally</a>, and technology progress and innovation continue apace to support a transition to clean energy.</p><p>In the U.S. under a Biden administration, long-term national climate legislation will depend on who controls the Senate, and that won't be clear until after two run-off elections in Georgia in January.</p><p>But there is no shortage of <a href="https://www.bloomberg.com/features/2020-biden-climate-change-advice/" target="_blank">ideas for ways Biden</a> could still take action even if his proposals are blocked in Congress. For example, he could use executive orders and direct government agencies to tighten regulations on greenhouse gas emissions; increase research and development in clean energy technologies; and empower states to exceed national standards, <a href="https://www.reuters.com/article/us-autos-emissions-california/defying-trump-california-locks-in-vehicle-emission-deals-with-major-automakers-idUSKCN25D2CH" target="_blank" rel="noopener noreferrer">as California did in the past with auto emission standards</a>. A focus on a just and equitable transition for communities and people affected by the decline of fossil fuels will also be key to creating a sustainable transition.</p><p>The U.S. position as the world's largest oil and gas producer and consumer creates political challenges for any administration. U.S. forays into European energy security are often treated with suspicion. Recently, France blocked <a href="https://www.wsj.com/articles/frances-engie-backs-out-of-u-s-lng-deal-11604435609" target="_blank">a multi-billion dollar contract</a> to buy U.S. liquefied natural gas because of concerns about limited emissions regulations in Texas.</p><p>Strengthening cooperation and partnerships with like-minded countries will be critical to bring about a transition to cleaner energy as well as sustainability in agriculture, forestry, water and other sectors of the global economy.</p>
Creating a Global Sustainable Transition<p>How the world recovers from COVID-19's economic damage could help drive a lasting shift in the global energy mix.</p><p>Nearly one-third of Europe's US$2 trillion economic relief package <a href="https://www.bloomberg.com/news/articles/2020-07-21/eu-approves-biggest-green-stimulus-in-history-with-572-billion-plan" target="_blank" rel="noopener noreferrer">involves investments that are also good for the climate</a>. The European Union is also strengthening its 2030 climate targets, though each country's energy and climate plans will be critical for successfully implementing them. The <a href="https://joebiden.com/clean-energy/" target="_blank" rel="noopener noreferrer">Biden plan</a> – including a $2 trillion commitment to developing sustainable energy and infrastructure – is aligned with a global energy transition, but its implementation is also uncertain.</p><p>Once Biden takes office, Kerry will be joining ongoing <a href="https://www.un.org/en/conferences/energy2021/about#:%7E:text=The%20overarching%20goal%20of%20the,2030%20Agenda%20for%20Sustainable%20Development.&text=Accelerate%20delivery%20of%20United%20Nations,related%20issues%20at%20all%20levels." target="_blank" rel="noopener noreferrer">high-level discussions on the energy transition</a> at the U.N. General Assembly and other gatherings of international leaders. With the U.S. no longer obstructing work on climate issues, the G-7 and G-20 have more potential for progress on energy and climate.</p><p>Lots of technical details still need to be worked out, including international trade frameworks and standards that can help countries lower greenhouse gas emissions enough to keep global warming in check. <a href="https://www.carbonpricingleadership.org/what" target="_blank" rel="noopener noreferrer">Carbon pricing</a> and <a href="https://www.csis.org/analysis/how-can-europe-get-carbon-border-adjustment-right" target="_blank" rel="noopener noreferrer">carbon border adjustment taxes</a>, which create incentive for companies to reduce emissions, may be part of it. A consistent and comprehensive set of national energy transition plans will also be needed.</p><p>The global shift to <a href="https://www.irena.org/publications/2019/Jan/A-New-World-The-Geopolitics-of-the-Energy-Transformation" target="_blank">clean energy will also have geopolitical implications for countries and regions</a>, and this will have a profound impact on wider international relations. Kerry, with his experience as secretary of state in the Obama administration, and Biden's plan to make the climate envoy position part of the National Security Council, may help mend these relations. In doing so, the U.S. may again join the wider community of countries willing to lead.</p>
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By Maria Caffrey
As we approach the holidays I, like most people, have been reflecting on everything 2020 has given us (or taken away) while starting to look ahead to 2021.
We Need More Than Listening<p>By now we have all become sadly accustomed to the current administration sidelining scientists, most prominently Dr. Anthony Fauci, because the facts they provide do not fit with the political rhetoric of the moment.</p><p>I have <a href="https://www.csldf.org/2019/08/22/csldf-helps-climate-scientist-maria-caffrey-fight-for-scientific-integrity/" target="_blank">my own history</a> of filing a scientific integrity complaint with the National Park Service (which falls under the Department of the Interior) after senior ranking employees attempted to censor one of my scientific reports. I know all too well the damage and pain that these actions cause, not just for the individual scientist, but also because these <a href="https://www.ucsusa.org/resources/attacks-on-science" target="_blank" rel="noopener noreferrer">attacks on science</a> over the last few years have undermined sound, evidence-based decision making.</p><p>President-elect Biden has repeatedly said that he will <a href="https://thehill.com/homenews/521638-trump-biden-will-listen-to-the-scientists-if-elected" target="_blank" rel="noopener noreferrer">listen to the scientists</a>. While this is certainly a welcome change, listening can only take us so far. This past week Lauren Kurtz from the <a href="https://www.csldf.org/" target="_blank" rel="noopener noreferrer">Climate Science Legal Defense Fund</a> and my colleague <a href="https://www.ucsusa.org/about/people/gretchen-goldman" target="_blank" rel="noopener noreferrer">Gretchen Goldman</a> published <a href="https://www.scientificamerican.com/article/ten-steps-that-can-restore-scientific-integrity-in-government/" target="_blank" rel="noopener noreferrer">an article</a> listing 10 actions the new administration should implement to show their commitment to strengthening government science:</p><ol><li>Clearly prohibit political interference and censorship.</li><li>Protect scientists' communication rights.</li><li>Acknowledge that attempts to violate scientific integrity, even if ultimately not fruitful, are still violations.</li><li>Protect federal scientists' right to provide information to Congress and other lawmakers.</li><li>Commit to incorporating the best science as part of agency decisions.</li><li>Elevate agency scientific integrity policies to have the full force of law.</li><li>Publicly release anonymized information about scientific integrity complaints and their resolutions at every agency.</li><li>Institute an intra-agency workforce, potentially under the White House <a href="https://www.ucsusa.org/sites/default/files/2020-09/strengthening-science-and-si-at-ostp.pdf" target="_blank" rel="noopener noreferrer">Office of Science and Technology Policy</a>, to coordinate scientific integrity efforts across agencies, foster discussion of policy improvements, and standardize criteria for policies across agencies.</li><li>Strengthen whistleblower protections.</li><li>Ensure that policies cover all actors who will be dealing with science.</li></ol>
Time for Action<p>I have spoken to many scientists, particularly federal scientists, who are eager to turn the page so they can hurry back to the work they had been doing before this administration, but I urge caution in assuming that things can be "normal" again.</p><p>Before Trump, I naively thought the scientific integrity policies established during the <a href="https://obamawhitehouse.archives.gov/blog/2016/12/19/scientific-integrity-policies-update" target="_blank">Obama administration</a> would be sufficient. I never imagined that any administration could so willfully ignore and attack expert advice and evidence that is intended to protect us and our public lands.</p><p>I have personally witnessed how hard our federal scientists work. They put in long hours with minimal pay (far less that what they could get if they worked in private industry) to pursue one simple goal: to make things better for the nation.</p><p>We need stronger scientific integrity policies to protect these people and their work. But more than that, we need stronger scientific integrity laws because they also benefit society.</p>
By Andrea Germanos
Environmental campaigners stressed the need for the incoming Biden White House to put in place permanent protections for Alaska's Bristol Bay after the Trump administration on Wednesday denied a permit for the proposed Pebble Mine that threatened "lasting harm to this phenomenally productive ecosystem" and death to the area's Indigenous culture.
<div id="da98c" class="rm-shortcode" data-rm-shortcode-id="478a197b7c59c92787c92bec92f1ac39"><blockquote class="twitter-tweet twitter-custom-tweet" data-twitter-tweet-id="1331662923710693376" data-partner="rebelmouse"><div style="margin:1em 0">Bristol Bay forever, Pebble mine never. #NoPebbleMine #SaveBristolBay https://t.co/CBQ9zuy8A5</div> — Save Bristol Bay (@Save Bristol Bay)<a href="https://twitter.com/SaveBristolBay/statuses/1331662923710693376">1606328156.0</a></blockquote></div>
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OlgaMiltsova / iStock / Getty Images Plus
By Gwen Ranniger
In the midst of a pandemic, sales of cleaning products have skyrocketed, and many feel a need to clean more often. Knowing what to look for when purchasing cleaning supplies can help prevent unwanted and dangerous toxics from entering your home.