Leila Battison

WORK TOGETHER

Tag: nature

  • Why Some Earthquakes Hit Harder Than Others

    Why Some Earthquakes Hit Harder Than Others

    On May 5th 2024, a 4.8 magnitude earthquake shook New Jersey. It was the first sizeable quake the region had seen in years, and it made headlines across the US. What struck me, though, was how different the response was compared to the west coast, where quakes of that size happen fairly often without much fuss.

    That contrast became the focus of a SciShow episode I wrote recently. On the surface, a 4.8 is a 4.8, no matter where it happens. But as I dug into the research, I was reminded that geology has a way of complicating even the neatest numbers.

    The Richter scale, devised back in 1935, gave us a standard way of measuring quakes, but it was built on data from California and never really worked worldwide. These days, scientists use moment magnitude instead. It’s a more robust calculation that takes into account the properties of the rocks and the fault itself. Still, even that number can’t tell you everything about what an earthquake will feel like.

    The real story is in the rocks. On the east coast, the crust is old, dense, and continuous, so seismic energy can travel astonishing distances. That’s why a 5.8 quake in Virginia in 2011 was felt almost 1,000 kilometers away, while a stronger quake in California barely carried half as far.

    Then there’s the effect of what’s underfoot. If you’re standing on solid bedrock, the shaking might feel sharp but brief. But if you’re on softer sediments, the waves get amplified and drawn out. Mexico City, Christchurch, Los Angeles, all cities built on basins and old lakebeds, have all suffered devastating consequences from this “jello effect.”

    One of the most fascinating (and sobering) examples I came across was the 2001 Gujarat earthquake in India. It measured 7.7 in magnitude and was felt over 1,000 kilometers away, causing tens of thousands of deaths. Just three years later, the enormous Sumatra-Andaman quake struck with a magnitude over 9. While it unleashed a catastrophic tsunami, the shaking itself wasn’t felt nearly as far afield. Same planet, same process, but completely different outcomes because of local geology.

    Writing this episode was a good reminder that magnitude isn’t the whole story. Whether an earthquake feels like a distant rumble or topples buildings depends on the deep, complicated history written into the rocks beneath us.

    Watch the full video here:

  • The World’s Biggest Geode (and How It Saved a Winery)

    The World’s Biggest Geode (and How It Saved a Winery)

    Like many children, I was captivated by museum gift shops, especially the shelves of glittering geodes. Crack one open and you’re rewarded with a surprise display of crystals hidden inside. Those pocket-sized treasures, though, are nothing compared to the largest geode in the world – one so vast it could swallow the entire gift shop whole.

    Interior of a geode cave with large, crystalline formations on the ceiling, two visitors gazing in awe at the stunning mineral display.

    The story begins in 1897 on South Bass Island, Ohio, where German-American winemaker Gustav Heineman had set up a vineyard. When he ordered a well to be dug to supply water for his vines, workers broke into a cavern 12 metres down. Instead of solid rock, they found a cave lined with enormous crystals.

    The cave’s origins trace back hundreds of millions of years. During the Silurian period, 430 million years ago, this part of North America was covered by shallow seas. Layers of sedimentary rock formed, including lenses of the evaporite mineral anhydrite (calcium sulfate). Fast forward to the end of the last Ice Age: meltwater from retreating glaciers and nearby Lake Erie seeped through the rocks, dissolving the anhydrite and leaving behind empty cavities.

    Normally, these spaces might become crystal-lined geodes filled with quartz or amethyst. But here, something unusual happened. The groundwater was rich in strontium. As it interacted with the dissolving anhydrite, calcium ions were replaced by strontium, forming celestine – pale blue, glassy crystals of strontium sulfate. Over thousands of years, they grew to extraordinary sizes, some more than a metre across, filling the cavern with their sky-coloured sparkle.

    The cave, however, didn’t remain untouched. In the early 20th century, miners extracted around 150 metric tons of celestine crystals, not as souvenirs but as a source of strontium for the fireworks industry, where it produced a brilliant crimson flame. The removal enlarged the cavern to its current size – 11 metres across and tall enough to stand in.

    Recognising an opportunity, Heineman’s son Norman opened the cave to visitors in 1919. The timing was fortuitous: during Prohibition, when most Ohio wineries were forced to shut, ticket sales to the “Crystal Cave” (along with grape juice) kept the business alive.

    Today, more than a century later, the Heineman Winery and its glittering celestine cavern still welcome tourists, making South Bass Island home to both award-winning wines and the largest geode on Earth.

    This year I’ve had the pleasure and privilege of writing a series of mineral-focused scripts for SciShow’s limited-run Rocks Box subscription. It’s been such a joy being able to nerd out about rocks and minerals. I’ll write about anything, but geology will always be my first love. Watch this space for many more rocks-related updates!

    Watch the full video from SciShow here:

  • Epidote: The Green Mineral That Could Hold Clues to Life’s Origins

    Epidote: The Green Mineral That Could Hold Clues to Life’s Origins

    At first glance, epidote might look like a perfectly ordinary rock: greenish, slightly glassy, nice enough to put on your bookshelf. But this mineral is far more than just decoration. Epidote could help unlock the mystery of life’s earliest origins on Earth, and perhaps even beyond.

    The fossil record is our best archive for understanding the history of life, but it has limits. The deeper back in time you go, the harder it becomes to find intact fossils. Earth’s plate tectonics are constantly recycling rocks, and the fossils that do survive tend to be battered, squashed, or melted beyond recognition. Add to this the fact that the earliest life forms were likely tiny, soft, and strange-looking, and the trail of evidence gets very faint indeed.

    That’s where minerals like epidote come into play. Formed when hot fluids percolate through volcanic rocks in a process known as epidotization, this mineral often appears in striking pistachio-green veins. On Earth today, these hydrothermal systems occur at places like mid-ocean ridges and subduction zones, where scalding fluids rise from cracks in the crust to form black smoker chimneys. Despite the heat, these are thriving ecosystems, and many scientists think they resemble the extreme environments where life first emerged billions of years ago.

    Because epidote is a signature of ancient hydrothermal activity, finding it in very old rocks can point us to past habitats where early microbes might have lived. That’s exactly what researchers in the Pilbara region of northwestern Australia have been doing. The Pilbara hosts some of the world’s oldest rocks, dating back 3.5 billion years, along with some of the earliest fossil evidence of simple, bacteria-like life. These fossils are fragmentary, but the presence of epidotized rocks helps scientists target the ancient hydrothermal systems where life may once have thrived.

    Epidote isn’t just about Earth’s history either. Since it flags hydrothermal activity, and by extension, potential habitability, it’s also a mineral of interest on Mars. NASA’s Spirit and Opportunity rovers have already detected trace amounts of epidote on the Red Planet, and future missions will keep watch for more. If found in the right context, those green veins could be a roadmap to places where Martian life once might have had a chance.

    So, next time you see a small green crystal of epidote, remember: it’s more than just a mineral. It’s a window into life’s extreme beginnings, and perhaps a guide to finding it elsewhere in the solar system.

    This year I’ve had the pleasure and privilege of writing a series of mineral-focused scripts for SciShow’s limited-run Rocks Box subscription. It’s been such a joy being able to nerd out about rocks and minerals. I’ll write about anything, but geology will always be my first love. Watch this space for many more rocks-related updates!

    Watch the full video from SciShow here: