When you think about it, the Earth has had a rough time of it. You’d never guess by looking, but over its 4.5 billion year history it’s been hit a zillion times by asteroids, from dust motes up to something Mars-sized that whacked us and ended up forming the Moon.
You’d expect the planet to be scarred, pockmarked, from all this. But the Earth is restless, and shifty. Even though there probably isn’t a square meter of the planet that hasn’t been hit, over millions of years erosion has taken its toll, wiping out all but a few of the craters.
Some are obvious enough, like Barringer Crater in Arizona. I’ve been there, and it’s amazing. But the one that wiped out the dinosaurs is 100 or more kilometers across, and most of it’s underwater. It takes some pretty sophisticated technology to even know it’s there.
So what’s a crater aficionado to do? Why, go to the Impact Field Studies Group homepage, of course. This group is like Audubon for extinction-level events; they travel around doing field studies at impact sites. The site has pictures (the panorama above is from their page; click it for a better image and a bunch more), descriptions, and this is way cool, an Excel spreadsheet listing 540+ suspected impact sites across the planet. Want a nightmare? Sort them by crater diameter. Yikes.
September 13th, 2005 at 7:00 pm
I live in the second largest crator on Earth right now. Good old Sudbury Ontario.
September 13th, 2005 at 10:53 pm
Lonar crater, Maharashtra, India on Google Maps:
http://maps.google.com/maps?ll=19.977059,76.507759&spn=0.074334,0.117090&t=k&hl=en
September 14th, 2005 at 5:15 am
I always though Manicouagan, in Quebec was cool. The reservoir formed around it makes it really stand out in satellite images, and there’s something of it that reminds me of some kind of landscape or domain in a fantasy novel – almost Tolkien-esque. You know, huge circular lake with a peak in the middle.
http://neo.jpl.nasa.gov/ images/manicouagan.html
CJSF
September 14th, 2005 at 5:16 am
repost of URL without annoying uneditable space:
http://neo.jpl.nasa.gov/images/manicouagan.html
CJSF
September 14th, 2005 at 7:06 am
Exploration of terrestrial meteorite craters is a hobby of mine actually. I have documented these trips in the Royal Astronomical Society of Canada (RASC) website:
http://www.ottawa.rasc.ca/astronomy/earth_craters/index.html
I just came back from flying over the “suspected” meteorite crater Merewether (soon to be published on the website).
Chuck
September 14th, 2005 at 8:52 am
A question from a layperson — how long does it take for the effects from a meteor strike (like the one in Arizona or the one in Quebec) to subside? For the crater to erode to less sharp edges, for the detrius and ejecta to get washed/blown away, for flora and fauna to come back into the area, etc?
I ask because I work for a Young Earth Creationist, and I am wondering if I can point to impact craters as an example of something that could not have happened if the earth is only 10,000 years old. Not that he’s going to change his mind, of course, but more ammo is always nice.
September 14th, 2005 at 10:13 am
RE: Question by Jeff Hebert – AGE of Meteorite Craters
Jeff:
One of the better references to your question is at:
http://www.infidels.org/library/modern/dave_matson/young-earth/specific_arguments/meteor.html
…. but take my word for it, you are wasting your time trying to discuss anything scientific with a creationist.
September 14th, 2005 at 12:59 pm
THE PHOTOS ARE MISSING THE NEW QUEBEC CRATER LOCATED IN THE UNGAVA BAY PENINSULA IN NORTHEN QUEBEC
HERE IS LINK http://www.unites.uqam.ca/tuvaaluk/ milieu_physique/FrCratNQ2.html
September 15th, 2005 at 8:17 am
At Google Globetrotting, we have a whole category of Google Maps links to Craters. The category is a mix of impact and volcanic craters, but there are a lot of impact craters listed.
http://googleglobetrotting.com/show.php/t/cat/cat/67/s/0
September 15th, 2005 at 10:37 am
Thanks Charles. You’re right, there’s very little point in arguing any more (which doesn’t stop us of course), but the link was very educational. I appreciate your taking the time to post it.
Jeff
September 15th, 2005 at 6:16 pm
Is it just me or are Sweden and Finnland really that dangerous? I had a look at the SEIS map, and there seems to be a huge concentration of impact sites in those two countries.
September 18th, 2005 at 6:05 pm
This is a fascinating blog. I look forward to learning more and more here! Keep up the great work.
September 19th, 2005 at 10:53 am
Tommy B: I think it might be that the rock there is older (pre-cambrian) and less eroded than other places. Parts of eastern Canada are similar – the geology there is among the oldest in the world. The arctic/subarctic regions of the northern hemisphere have a fortuitous blend of old rock, glaciation and aridity. Other places that have similarly aged rock tend to be in areas that did not experience much glaciation (to remove overlying rock and soil) or are in moist climates – which means the craters tend to erode away.
CJSF
December 28th, 2005 at 2:13 pm
If you’d like to see those impact craters in Google Earth take a look at my page (http://www.thinklemon.com/pages/ge/). I’ve put size indicators per crater, so you can compare sizes.
BTW: Vredefort, Sudburry, Manicouagan and Acraman are awesome. To name a few.
BTW2: If I can get my hands on it, I’ll add the ‘Suspected Earth Impact Sites’. The site is pretty darn slow…