Issue 74: Water Quality
May 4, 2023
In this week’s issue:
- Satellites monitor water pollution
- A new blue hole is discovered
- Shiveluch erupts
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Feature Story: Water Quality
Last week we talked about the world’s second most extracted resource: sand. And like any well-structured award show, we saved first for last. It should come as no surprise that we rely most on Earth’s supply of water. It makes up 60% of our bodies and covers 71% of our planet. We’re water-fanatics in a watery world. Yet we increasingly treat it as waste, dumping everything from oil to fertilizers in it. If we are what we drink, then there’s an argument that we’re a bacterial, plasticky waste.
It can be hard to distinguish where we begin and water ends. It’s around, over, under, and within us at all times. Which unfortunately means it’s rather easy to contaminate. Water sources intersect with both our industries and our mistakes, which together lead to a series of water crises. It’s a pollution problem with massive stakes. More people die from unsafe drinking water than war or violence every year.
Though it’s not quite as out of sight as sand extraction, water pollution is a major issue and at times a pronounced crisis. So this week, we’re taking a look at a few common ways Earth’s water is contaminated and, in some cases, how satellites can help on-the-water action.
US news this month has focused on certain objects slowly moving towards the country’s coasts: balloons in the sky and sargassum in the sea. A 4,000-mile (6,400-km) belt of the macroalgae bloomed in the Atlantic and is now moving towards the Caribbean Sea and Gulf of Mexico. Once it washes ashore, it releases toxic (and foul smelling) chemicals. So projects like SargAssure use satellite data to track its movements and alert those in its impending path.
If you’re wondering why this issue has already featured two images of toxic algal blooms, it’s not just because our editor loves Shrek and other intimidating green giants. It’s because they’re a widespread problem. Algal blooms often form as a result of excess nutrients, commonly due to fertilizer pollution. These events create aquatic dead zones that can contaminate drinking water and harm entire ecosystems.
A large part of keeping water clean is keeping dirty water out. And our friends at Ordnance Survey know all about that crappy business. Great Britain’s mapping agency uses satellite data to monitor sewage spills that often contaminate the area’s waterways. They paired this remote dataset with AI models to predict when an overspill event would occur, with the best of their models clocking in at a 91.5% correct prediction rate.
Even if it’s not direct contamination, managing water resources and understanding fluid dynamics can help regulators ensure a safe supply. Flushing accumulated sediment from dams and reservoir systems is critical to their effectiveness, so companies like EOMap use satellite data to monitor sediment redistribution.
Water is the root of many 21st century challenges: floods, drought, pollution, and rising demand. Because it’s both so pervasive and important for human populations, it’s difficult to even comprehend the number of ways we’re polluting Earth’s waterways, lakes, and oceans. But the good news is that maintaining a sustainable supply of clean water is doable. It may be impossible to step in the same river twice, but it is possible to make sure it’s cleaner the second time around.
In the News: Blue Holes
Our knowledge of the ocean’s blue holes just got a little deeper. Scientists recently released their findings of the second deepest blue hole recorded off the coast of the Yucatan Peninsula. The 900-foot (274-meter) deep Taam ja’ Blue Hole — Mayan for “deep water” — was found by fishermen and is now being studied for its unique seawater chemistry.
Like the black holes that dot space, blue holes are found all over. But information is still scant since these marine sinkholes are difficult to study. We’re a little sore that we’ll unlikely ever explore these black and blue mysteries, so in the meantime we’ll enjoy their mysterious and murky entrances from afar.
What in the World: Icy Eruption
Exit spy balloons, enter sulfur dioxide clouds. One of NASA/NOAA’s satellites captured a massive gas plume moving across the Pacific after Russia’s Shiveluch Volcano erupted in early April. We captured this oblique image of the ongoing eruption a few weeks after the initial blast, and we’re entranced by this Hoth-like result. But unlike the hot lasers and sabers of Star Wars, volcanic eruptions like these often have a net cooling effect since sulfur dioxide reflects incoming sunlight. May the 4th be with you, as they say.
All imagery Ⓒ 2023 Planet Labs PBC
Editor: Ryder Kimball | Images: Ryder Kimball, Robert Simmon, Max Borrmann, Julian Peschel, Candace Chow, and Maarten Lambrechts
