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  • California’s Sinking Valley

    California’s Sinking Valley
    Feb 24 2026
    California’s Central Valley is an agricultural bonanza, producing a third of America’s food crops. But it’s facing serious water challenges. The valley floor is 20,000 sq miles of some of the most fertile soil on Earth. Here, the sun shines 300 days a year. More than 250 different crops grow, worth $17 billion per year. The valley was developed into farmland around the turn of the twentieth century. When farmers arrived, they began to drill wells into the fresh-water aquifers below. By the 1930s, scientists began to notice an impact. Some of the aquifers, with their water levels and pressure drawn down, compacted. This meant they would never refill to earlier levels, and the land above them subsided. This continued into the 1970s, when sinking land, up to 30 ft in parts of the valley, had damaged roads, bridges, and buildings so dramatically that California spent millions to repair them and built canals to bring in water. The problem was alleviated—until conservation elsewhere in the state reduced water in the canals and valley farmers pulled hard on their wells again. The wells remained unregulated until 2012, when California passed serious water legislation. It will be decades before it’s fully phased in, but the hardest-hit areas are being addressed now. In the meantime, the valley floor and the water table continue to fall.
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    2 Min.
  • Hurricane Harvey

    Hurricane Harvey
    Feb 24 2026
    Harvey, like all major storms, did not discriminate. Its floods impacted poor and wealthy alike. Some neighborhoods were wiped out, while others were left untouched. And it left many wondering: could it happen again? Harvey was a so-called “500-year event.” This means that meteorologists project 1 in 500 odds that a flood of that size will happen in a given year. The incredible thing is that Harvey was the third 500-year flood in Houston in just 3 years. The odds of that happening are very long indeed. This suggests that the probability system may need to be revised, and that in the future, severe floods may be more likely. There is no “normal” in nature. It’s always changing. Nature doesn’t adapt to humans; humans must adapt to nature. Houston is located on a marshy plain. Its soils don’t drain well ... but they hardly drain at all when covered in concrete or asphalt. Houston has grown successfully, but future plans should maximize green space and minimize impermeable cover. Since its land is flat, the rivers and bayous that drain Houston are slow moving, and prone to overflow. The city must accelerate efforts to widen and improve them, and consider barriers to block storm surge from pushing water back up them. As population grows, there will be a temptation to expand into flood-prone areas. The city has been warning developers against this but should step up efforts. The good news is, with careful planning and management, Houston should be able to minimize the impact of future storms.
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    2 Min.
  • Venice Holds Back the Sea

    Venice Holds Back the Sea
    Feb 24 2026
    Just a few years ago, Venice, Italy, would flood more than 60 times a year. Until the Venetians decided to push back. All that water was due to where Venice is built—in the middle of a lagoon. And why was it built there? In the fifth century, Roman farmers, fleeing invaders, moved out to fishing huts on a string of low mud islands. Battered by tides, they built houses on stilts. But their protection worked. While barbarians pillaged Italy, Venice thrived. Their settlement grew into a city, which grew into the greatest naval power in the Mediterranean—with the whole thing built on stilts. Over the centuries, sediments beneath the city gradually compacted. The Venetians responded by jacking up their buildings farther. But in the twentieth century, drilling and extraction of groundwater and natural gas caused the city to sink faster, while the Adriatic Sea level rose. Tidal flooding became so frequent that Venice built a system of 79 enormous steel gates at the inlets to their lagoon. Each gate is 100 ft tall and weighs 300 tons. It rests flat on the seafloor—till an overly high tide is predicted. Then, Venice pumps the gates full of air, and they slowly stand up, able to hold back 10 ft of ocean surge. When the threat is over, they sink back to the seafloor. There are many other subsiding cities, like New Orleans, Miami, and Jakarta, keeping a watchful eye on the sea—and on the amazing gates of Venice.
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    2 Min.
  • Cities Made of Sand

    Cities Made of Sand
    Feb 24 2026
    Sand. It circles the continents and stretches across deserts. There’s so much, you’d think we’d never run out. But in many places, we are. The term “sand” just refers to the size of the grain. It can be made of many materials, but the sand we value most is made of quartz. We use it to make glass, computer chips, roof shingles, paints, sealants, cosmetics, and much more. But we use it most in concrete, which is about two-thirds sand. There are hundreds of tons in the average American house—and billions of tons in cities. And therein lies the rub. Because sand is so heavy, it’s expensive to transport, meaning most sand used in buildings is local. And the rapid growth of new cities, particularly in China, India, and other developing countries, has used up much of the high-quality local supply. Beach sand is not a good choice for concrete—the salt can corrode the reinforcing steel. Yet some coastal cities and island nations have stripped their beaches bare for the building trade, leaving only rock. Other communities, like Dubai and Phoenix, use their local desert sand, which is often poor quality, as well. It’s high in clay, chalk, and iron oxide. Shortage of good-quality sand has led China to begin importing it. Elsewhere, like in India, a black market has sprung up, complete with sand mafias! In the future, we’re likely to see a growing global trade in this surprisingly precious commodity.
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    2 Min.
  • The Man in the Moon

    The Man in the Moon
    Feb 24 2026
    Every person in the Northern Hemisphere, when they look up at the full moon, sees a face like a smiling snowman—the man in the moon. Throughout history, he has inspired legends. In many European cultures, he was a man banished to the moon for stealing from his neighbors—or for working on Sunday. (Good thing that’s not a banishable offense today!) Coastal Germans, recognizing the moon’s tidal connection, believed he was a giant who poured water on Earth to create high tide. In Norse legend, the man kidnapped two children to have them fetch that water, a story that would become Jack and Jill. In the Southern Hemisphere, however, the man’s face is upside down, which makes it look like a rabbit—with legends all its own. The eyes of the man and the body of the rabbit are actually basalt flats caused by ancient lava flows. But why do all people on Earth see this same view? The answer is something called tidal locking—most moons are tidally locked to their planets. Soon after the moon formed, the powerful pull of Earth’s gravity created a bulge near the moon’s equator. Gravity kept pulling the bulge toward Earth, slowing the moon’s rotation till it was perfectly in synch with the moon’s orbit around Earth, meaning that only one side of it faces Earth, and always will. So what exactly is on the other side of the moon? You’ll have to wait till another EarthDate to find out.
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    2 Min.
  • Hadrosaur Hightails It

    Hadrosaur Hightails It
    Feb 24 2026
    Recently, scientists discovered the fossil of a hadrosaur, a duckbilled dinosaur, which was bitten by a Tyrannosaurus. A bite on a fossil is not that unusual, but this one helped settle an argument. Over the past few decades, some paleontologists maintained that T. rex was a ferocious hunter. Newer theories pointed to his useless forelimbs, small eyes, and huge olfactory chambers. He wouldn’t have been able to grasp prey and may have had poor vision—but he would have been able to smell a rotting carcass from miles away. In other words, he was likely a scavenger. But the hadrosaur tail vertebrae in this fossil were fused together around a T. rex tooth—the wound had healed. This meant that the hadrosaur was alive when it happened, and lived on. Which strongly suggests that T. rex did in fact chase and catch it—almost. This brought up another question: given his weaknesses, how did the tyrannosaur do it? A different set of scientists analyzed the leg mechanics of T. rex for bone stress. Proponents of “T. rex the hunter” had pointed to his speed, previously estimated at over 30 miles per hour. But this new research suggests that the foot bones, carrying his 7 tons of weight, would have shattered at that pace. The tyrannosaur’s top speed was probably just 12 miles per hour. And maybe that’s why the duckbill got away—T. rex may have been an occasional hunter, but maybe not a very good one.
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    2 Min.
  • Exploring Earth’s Driest Deserts

    Exploring Earth’s Driest Deserts
    Feb 24 2026
    In the 1970’s, the Viking rover landed on Mars and detected no life. In 2003, NASA took the same technology to the Atacama Desert in Chile and got the same reading. Was there really no life there? And by extension, no life on Mars? You might think that the driest place on Earth is the Sahara. But they’re actually polar deserts, like the McMurdo Dry Valleys of Antarctica, and high deserts, like the Atacama. There are places there where it hasn’t rained in 500 years—if ever. Surprisingly, the driest deserts are cold, not hot. That’s because cold air holds 20 times less water vapor than hot air. Though average temperatures in McMurdo are below freezing, the Atacama averages 70 degrees—but it’s in the rain shadow of both the Andes and the Chilean Coastal Range. It’s at 8,000 ft, where the air is very thin. And it’s near the equator, where solar radiation is extreme all year long. This is the most similar environment on Earth to Mars, which is why NASA is testing old and new Martian exploration technology here. While the Viking equipment missed any signs of life in the Atacama, new understanding of extremophiles—life found in extreme conditions—led NASA scientists to look beneath the soil and within rocks, where they found photosynthetic bacteria. And if life can exist here, in the most inhospitable place on Earth, we might also find it on the next mission to Mars.
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    2 Min.
  • Water from Thin Air

    Water from Thin Air
    Feb 24 2026
    Imagine you’re in Chile’s Atacama Desert, the driest nonpolar desert in the world. Understandably, you’re parched. So you head to the local watering hole…where you’re surprised to find a craft beer—made from fog. What? Deserts have little rain, but if they’re near the coast, they can have fog—which you may remember is just a cloud on the ground, water vapor condensing around particles in the air. In the Atacama, fogs often roll in from the Pacific, but the water droplets are too small to produce rain. So in the 1950’s, a professor began experimenting with ways to extract water from the cloud. Following his lead, the villagers of Peña Blanca have strung a series of nets in the mountains. Together, they condense more than 2,000 gallons of water from the fog each day, which is carried by aqueducts into the village. This water serves people, livestock, vegetable gardens—and an award-winning microbrewery. Their beers are famed for their light body, which some attribute to the lack of minerals in the cloud-borne water. Chilean researchers estimate that collecting just 4 percent of the water from the Atacama fog would meet the needs of all the communities in the desert, and that a 3-ft by 5-ft net could provide enough water for one person per day. For these reasons, villages in many countries are now building fog nets, and they could be an important source of water—and beer—in coastal deserts around the world.
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    2 Min.