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New freshwater database tells water quality story for 12K lakes globally – Phys.org

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A sunset caught over Boundary Lake in Ontario’s Killarney Provincial Park. Credit: Amanda Liczner

Although less than one per cent of all water in the world is freshwater, it is what we drink and use for agriculture. In other words, it’s vital to human survival. York University researchers have just created a publicly available water quality database for close to 12,000 freshwater lakes globally—almost half of the world’s freshwater supply—that will help scientists monitor and manage the health of these lakes.

The study, led by Faculty of Science Postdoctoral Fellow Alessandro Filazzola and Master’s student Octavia Mahdiyan, collected data for lakes in 72 countries, from Antarctica to the United States and Canada. Hundreds of the lakes are in Ontario.

“The database can be used by scientists to answer questions about what lakes or regions may be faring worse than others, how has changed over the years and which environmental stressors are most important in driving changes in water quality,” says Filazzola.

The team included a host of graduate and undergraduate students working in the laboratory of Associate Professor Sapna Sharma in addition to a collaboration with Assistant Professor Derek Gray of Wilfrid Laurier University, Associate Professor Catherine O’Reilly of Illinois State University and York University Associate Professor Roberto Quinlan.

The researchers reviewed 3,322 studies from as far back as the 1950s along with online data repositories to collect data on chlorophyll levels, a commonly used marker to determine and ecosystem health. Chlorophyll is a predictor of the amount of vegetation and algae in lakes, known as primary production, including invasive species such as milfoil.

York University researchers have created a publicly available water quality database for close to 12,000 freshwater lakes globally – almost half of the world’s freshwater supply – that will help scientists monitor and manage the health of these lakes. Credit: York University

“Human activity, , agricultural, urban runoff and phosphorus from can all increase the level of chlorophyll in lakes. The primary production is most represented by the amount of chlorophyll in the lake, which has a cascading impact on the phytoplankton that eat the algae and the fish that eat the phytoplankton and the fish that eat those fish,” says Filazzola. “If the chlorophyll is too low, it can have cascading negative effects on the entire ecosystem, while too much can cause an abundance of algae growth, which is not always good.”

Warming summer temperatures and increased solar radiation from decreased cloud cover in the northern hemisphere also contributes to an increase in chlorophyll, while more storm events caused by contribute to degraded water quality, says Sharma. “Agricultural areas and urban watersheds are more associated with degraded water quality conditions because of the amount of nutrients input into these lakes.”

The researchers also gathered data on phosphorous and nitrogen levels—often a predictor of chlorophyll—as well as lake characteristics, land use variables, and climate data for each lake. Freshwater lakes are particularly vulnerable to changes in nutrient levels, climate, land use and pollution.

New freshwater database tells water quality story for 12K lakes globally
Postdoctoral Fellow Alessandro Filazzola standing at the edge of David Lake in Ontario’s Killarney Provincial Park. Credit: Amanda Liczner

“In addition to drinking water, freshwater is important for transportation, agriculture, and recreation, and provides habitats for more than 100,000 species of invertebrates, insects, animals and plants,” says Sharma. “The database can be used to improve our understanding of how levels respond to global environmental change and it provides baseline comparisons for environmental managers responsible for maintaining quality in lakes.”

The researchers started looking only at Ontario lakes, but quickly expanded it globally as although there are thousands of lakes in Ontario a lot of the data is not as readily available as it is in other regions of the world.

“The creation of this database is a feat typically only accomplished by very large teams with millions of dollars, not by a single lab with a few small grants, which is why I am especially proud of this research,” says Sharma.

The research is published in Nature’s Scientific Data journal.


Explore further

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More information:
Scientific Data, DOI: 10.1038/s41597-020-00648-2

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York University

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New freshwater database tells water quality story for 12K lakes globally (2020, September 22)
retrieved 22 September 2020
from https://phys.org/news/2020-09-freshwater-database-quality-story-12k.html

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2.8-pound meteorite from space crashes into roof of Canadian woman’s home, falls on bed – The Tribune

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Tribune Web Desk

Chandigarh, October 16

Ruth Hamilton (66) had a disturbed awakening on October 3 when a large meteorite plunged from space, through her roof and landed in her bed.

Ruth, resident of Golden, British Columbia, woke up to the sound of a crash and her dog barking on October 3 around 11.35 pm.

Also read: Meteorite-like object falls from sky in Rajasthan; explosion heard 2-km away

Speaking with Canadian Press, she said: “I’ve never been so scared in my life, adding that, “I wasn’t sure what to do so I called 911 and, when I was speaking with the operator, I flipped over my pillow and saw that a rock had slipped between two pillows.”

She told CTV News: “I didn’t feel it.”

“It never touched me. I had debris on my face from the drywall, but not a single scratch.”

A police officer arrived on the scene, but suspected the object that landed in Hamilton’s bed was from a nearby construction site.

“He called the [construction site] and they said they hadn’t done a blast but that they had seen an explosion in the sky and, right then and there, we realised it was a meteorite,” she told the Canadian Press.

It turns out that the 2.8-pound space rock, about the size of a small cabbage, was part of a meteor shower identified by Alan Hildebrand, a planetary scientist in the Department of Geoscience at the University of Calgary, and his colleagues.

The group said the trajectory of the meteorite that hit Hamilton’s house would have made it visible throughout southeastern British Columbia and central and southern Alberta.

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Misconceptions about science fuel pandemic debates and controversies, says Neil deGrasse Tyson – CBC.ca

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Astrophysicist Neil deGrasse Tyson says some of the bitter arguments about medicine and science during the COVID-19 pandemic can be blamed on a fundamental misunderstanding of science.

“People were unwittingly witnessing science at its very best.… [They said,] ‘You told me not to wear a mask a month ago and now you tell me [to] wear it.… You don’t know what you’re talking about.’ Yes, we do,” the American astrophysicist and author told The Sunday Magazine host Piya Chattopadhyay.

“Science is a means of querying nature. And when we have enough experiments and enough observations, only then can we say: This is how nature behaves, whether you like it or not. And that is when science contributes to what is to what is objectively true in the world.”

Tyson, who is also the director at the Hayden Planetarium in New York City, is doing his part to try to make his corner of the scientific world more accessible with his new book A Brief Welcome to the Universe, co-authored with Michael A. Strauss and J. Richard Gott.

He hopes readers can take those lessons to other scientific topics, including the COVID-19 pandemic, which has seen several controversies flourish about the nature of the virus and the measures developed to fight it.

Misconceptions about how science works stems in part, he said, from the fact that it’s often improperly taught at the earliest levels of education.

“People think science is the answer. ‘Oh, give me the answer. You’re a scientist. What’s the answer?’ And then I say things like: ‘We actually don’t have an answer to that.’ And people get upset. They even get angry. ‘You’re a scientist. You should know,'” he explained.

“What’s not taught in school is that science is a way of learning what is and is not true. The scientific method is a way of ensuring that your own bias does not leave you thinking something is true that is not, or that something is not true that is.”

Big universe, simple language

A Brief Welcome to the Universe is billed as an approachable “pocket-sized tour” of the cosmos, answering such questions as “How do stars live and die?” and “How did the universe begin?”

It’s a condensed version of the 2016 edition of the book, Welcome to the Universe: An Astrophysical Tour.

Welcome to the Universe: A Pocket-Sized Tour is co-authored by Neil deGrasse Tyson, Michael A. Strauss and J. Richard Gott. (Princeton University Press)

Tyson and his co-authors argue in the book that astrophysics uses simpler language than other scientific disciplines, which makes it a good starting point to learn about science.

“I don’t simplify the origin of the universe and then call it ‘The Big Bang’ to you. We call it that to each other,” said Tyson. The same goes for well-known phenomena like black holes, sunspots and the planet Jupiter’s Great Red Spot, he added.

Start with those, and then you can move onto other topics, some with more complex names — such as the Coriolis force, which, among other things, explains how the Earth’s rotation subtly affects the way a football travels in the air during a field kick.

“There are simple things in science. And if you’re interested, you can then go out and learn the complex things. But I’m not going to lead with the complex things. What good is that? That never solved anything,” he said.

Many people likely know Tyson from his appearances on American talk shows, often critiquing or debunking questionable science seen in movies and other pop culture. He’s commented on everything from the feasibility of resurrecting dinosaurs, like in Jurassic Park, to the improper night-sky backdrop in the final scenes of Titanic.

Tyson, left, and Seth MacFarlane, executive producer of Cosmos, participate in the Television Critics Association’s winter presentations in Pasadena, Calif., on Jan. 13, 2014. (Kevork Djansezian/Reuters)

He also talks about science on his podcast StarTalk, as well as on a National Geographic TV show of the same name and another show called Cosmos.

Tyson was temporarily removed from both programs in late 2018, after accusations of sexual misconduct from two women, which he denied. Following an investigation, in early 2019, National Geographic and Fox reinstated Tyson on their shows. They did not address the allegations in their statement announcing the decision.

About Pluto

Perhaps none of the topics Tyson is known for speaking about has sparked more discussion than Pluto, the former ninth planet.

“Oh, don’t get me started,” Tyson responded immediately upon mention of the icy celestial body, which was demoted from planet to dwarf planet status in 2006 by the International Astronomical Union.

The term “dwarf planet” is relatively new. It grouped Pluto, which was originally discovered in 1930, with a number of other icy bodies larger than an asteroid but smaller in size and mass to rocky planets closer to the Sun, including the Earth.

NASA’s New Horizons spacecraft captured this high-resolution, enhanced-colour view of Pluto on July 14, 2015. Once considered the solar system’s ninth planet, it was reclassified as a dwarf planet in 2006. (NASA/JHUAPL/SwRI)

“The word planet really should be discarded,” he said. “Because if I say I discovered a planet orbiting a star, you have to ask me 20 more questions to get any understanding of what the hell the thing is.”

The word “planet” comes from the Greek planetes, meaning “wanderer.” In ancient times, that included Mercury, Venus, Mars, Jupiter and Saturn, but also the moon and the sun. Earth wasn’t considered a planet, because it was believed to be the unmoving centre of the known universe.

Over time, the scientific method progressed beyond that: the Earth is a planet that orbits the sun, which is a star. We now know our moon is one of at least 200 moons in the solar system.

To Tyson, Pluto’s reclassification represents the next step in our evolving understanding of the cosmos, which has necessarily become more complex.

It also illustrates a broadening of our scientific horizons that ancient civilizations might have never contemplated.

That’s why when Tyson was asked how to best answer a child’s question about things we do not know, such as “how big is the universe,” he said the best thing we can say is that we do not know.

“That is one of the greatest answers you can ever give someone — because it leaves them wanting for more. And they might one day be the person who discovers what the answer will be.”


Written by Jonathan Ore. Produced by Sarah-Joyce Battersby.

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2.8-pound meteorite from space crashes roof of Canadian woman’s home, falls on bed – The Tribune India

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Tribune Web Desk

Chandigarh, October 16

Ruth Hamilton (66) had a disturbed awakening on October 3 when a large meteorite plunged from space, through her roof and landed in her bed.

Ruth, resident of Golden, British Columbia, woke up to the sound of a crash and her dog barking on October 3 around 11.35 pm.

Speaking with Canadian Press, she said: “I’ve never been so scared in my life, adding that, “I wasn’t sure what to do so I called 911 and, when I was speaking with the operator, I flipped over my pillow and saw that a rock had slipped between two pillows.”

She told CTV News: “I didn’t feel it.”

“It never touched me. I had debris on my face from the drywall, but not a single scratch.”

A police officer arrived on the scene, but suspected the object that landed in Hamilton’s bed was from a nearby construction site.

“He called the [construction site] and they said they hadn’t done a blast but that they had seen an explosion in the sky and, right then and there, we realised it was a meteorite,” she told the Canadian Press.

It turns out that the 2.8-pound space rock, about the size of a small cabbage, was part of a meteor shower identified by Alan Hildebrand, a planetary scientist in the Department of Geoscience at the University of Calgary, and his colleagues.

The group said the trajectory of the meteorite that hit Hamilton’s house would have made it visible throughout southeastern British Columbia and central and southern Alberta.

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