As everyone is aware, the Gulf looks like the remnant of a giant crater. Is anyone aware of any geological proof that it was created by the impact of a large meteor or asteroid? I don’t think I’ve ever heard any mention of this, yet it seems obvious on the face of it.
No, plate tectonics:
There is of course the theory that a meteor strike in the Yucatan led to the extinction of the dinosaurs.
Specifically the Chicxulub crater is evidence that such a strike occurred. Whether or not it truly led to the extinction events is the matter of debate, not whether or not a strike happened.
But that wasn’t nearly large enough to create the Gulf, of course. A 10 km (6 mile) wide asteroid is huge, devastatingly huge, but the Gulf is 1,500 km (810 miles) wide at its widest point. For an asteroid to create such a large space is…
Consider this. When an object strikes the earth and makes a crater, it is usually 10-20 times the width as the depth. So, if this was a crater, for it to be 1,500 km wide it would be 75-150 km (47-93 miles) deep. The deepest part of the ocean is the Challenger Deep in the Pacific Ocean, which at its deepest is almost 11 km. So why isn’t the Gulf that deep?
Basically, when you say:
It really doesn’t. It’s relatively shallow for its width if it was actually a crater. The deepest part of the Gulf is less than 4.5 km.
And any impact that did create a crater that large would have had absolutely devastating effects worldwide (it’d be much worse than the one that killed off the dinosaurs).
That’d be not quite “Spall off the Moon”-sized. But it would have been “Spall off a second rather large Moon2 to go along with the original Moon1”-sized.
All in all, be a bad day to be a passenger on Earth. I’ll pass, thank you.
I realize its shallow for its size, but take a look at mare Imbrium on the moon. It and other mare are thought to be much more ancient than 65my. They were formed in the range of billions of years old not millions — while the earth itself was taking shape. They have been eroded away and filled in by techtonics and lava flows.
Any impact big enough to make the Gulf of Mexico would leave other evidence in the rocks. We see no such evidence.
Yup…that’s it:
No, North and South America pulling apart created it.
The video shows it to have occurred around 173 million years ago, in the Jurassic. The Gulf is the gap left when Yucatan moved south.
Here’s a nice article on the origins of gas and oil deposits in the Gulf of Mexico that contains some information on its origins and history. Note that it went thru several cycles of drying out and refilling that left behind the salt layers that trapped the organic deposits. The refilling was initially from the Pacific Ocean (!) and later the Atlantic. Which is reason not to suppose the current basin boundaries correspond to the boundaries 100+ million years ago.
Also, remember that Florida barely sticks out of the water. It’s just a slightly higher bit of seabed. It’s definitely not the remnants of a crater rim.
If you want a weirdly circular landform that looks like it must be a meteor crater but probably isn’t, check out the Nastapoka Arc on the eastern shore of Hudson Bay.
Last year, a Canadian man was perusing Google maps while trying to find a place to hike, and found what appears to be a meteorite impact crater (link).
From that article: “it is thought to have been formed as a result of lithospheric flexure during the Trans-Hudson orogeny.”
I love nerd talk.
Here’s a better known one, also in Canada - The Eye of Quebec.
Thinking about the question in the OP, and considering the size difference between the Gulf and actual meteor craters, if the Gulf was created by one, it would likely be of planet-ending size, no? It would have to be a moon-sized object striking the earth squarely at high velocity to create a wound that big, I would think.
Kind of sounds dirty, doesn’t it? (link is SFW, don’t worry)
Mare Imbrium is about 1200km in dia. There are other large Mare on the moon that were formed when the Solar System was young, say 3.5 to 4.5 billion yr. It is certain that many large meteors (Asteroids) hit the Earth during this same time period. It likely would have taken an asteroid of about 1/10 to 1/20 the dia of Mare depending on the velocity. The low heights of the surrounding topography is not unexpected and might be explained by the existence of weather on the earth and its great age. The shallowness may be a product of the flow of liquified rock and magma as on the moon.