Spanish Shipwrecks Unveil Centuries of Hurricane Patterns

Dead men tell no tales—but it turns out Caribbean shipwrecks can tell us about the climate in the days of yore.

Scientists studying how climate change influences hurricanes have been faced with a problem: the U.S. only started keeping track of the storms in 1851. To figure out hurricane patterns of the deeper past, researchers needed a different record.

During the Age of Sail, hurricanes were the primary cause for shipwrecks in reports from that time. The researchers looked at records of Spanish ships in the Caribbean Sea from 1495-1825, and the list of shipwrecks told a riveting tale. While dozens of vessels sunk each year in stormy periods, 1645-1715 was a better time for the Spanish fleet, with only a few ships sinking each year.

Bountysinking
A replica of the HMS Bounty sunk in 2012 after its captain sailed it into the path of Hurricane Sandy.

It turns out that this period was one of global cooling, often called the Maunder Minimum or “Little Ice Age.” During this time, the sun’s light dimmed, cooling the planet and leading to more El Niño events that keep the Atlantic from producing large storms.

To compare this record to something we can measure today, the researchers looked at tree rings in Florida slash pines, which date back to 1707. The pines grow more slowly in years with hurricanes, and growth rings from that time confirm the storm pattern suggested by the shipwrecks. Combining what they learned from the pines, shipwrecks, and modern records, the scientists patched together a picture of how a cooler climate put the brakes on the development of hurricanes in the Atlantic.

The study could have important uses in predicting what might happen with tropical cyclone frequency if the planet’s atmosphere warms.

Here’s Chris Mooney, reporting for the Washington Post:

The result does not lead to any forecast when it comes to the hurricanes of the future, but at the same time, it’s certainly suggestive. After all, hurricanes derive their energy from the heat stored in tropical oceans. If seas are cooler — as they were between 1645 and 1715, when the Earth received less radiation from the sun — then there’s less explosive energy for storms to draw upon. If they’re warmer, as they are today, then all else being equal, there’s more opportunity for extreme storm intensification.

Even though most of us don’t sail in tall ships these days, this study suggests that  people living on the coast might have to batten down the hatches if the climate continues to warm.