November 1, 2007
1 min read
Add Us On GoogleAdd SciAmHigher Power
Earth's heat keeps continents afloat and land above sea level
By Sarah Simpson
On supporting science journalism
If you're enjoying this article, consider supporting our award-winning journalism by subscribing. By purchasing a subscription you are helping to ensure the future of impactful stories about the discoveries and ideas shaping our world today.
Topography seems easy to explain when beholding jagged summits such as Colorado’s Rocky Mountains or California’s Sierra Nevada range. After all, these mountains mark spots where the continent grew thick during violent collisions with other tectonic plates: the land crumpled and heaved skyward, like the hood of a car buckling in a head-on crash.
But surface-shaping geologic forces account for surprisingly little of the planet’s highs and lows. About half of North America’s elevation actually results from the planet’s internal heat. Minus that warmth, most land would sink below sea level, say University of Utah geophysicists Derrick Hasterok and David S. Chapman. Based on their recent calculations, parts of the Rockies and high Sierras would shrink to mere islands, whereas cities such as New York, Los Angeles and even mile-high Denver would slip 200 meters (700 feet) or more underwater.
It’s Time to Stand Up for Science
If you enjoyed this article, I’d like to ask for your support. Scientific American has served as an advocate for science and industry for 180 years, and right now may be the most critical moment in that two-century history.
I’ve been a Scientific American subscriber since I was 12 years old, and it helped shape the way I look at the world. SciAm always educates and delights me, and inspires a sense of awe for our vast, beautiful universe. I hope it does that for you, too.
If you subscribe to Scientific American, you help ensure that our coverage is centered on meaningful research and discovery; that we have the resources to report on the decisions that threaten labs across the U.S.; and that we support both budding and working scientists at a time when the value of science itself too often goes unrecognized.
In return, you get essential news, captivating podcasts, brilliant infographics, can't-miss newsletters, must-watch videos, challenging games, and the science world's best writing and reporting. You can even gift someone a subscription.
There has never been a more important time for us to stand up and show why science matters. I hope you’ll support us in that mission.