Space rock impact site(s)

[Turtle]

...The satellite photography is proving its worth in identifying areas worth further investigation, and looking at the other structures may help refine our skills at ID'ing these critters. We are on the cutting edge -or is that ground floor?- of a resource previously unavailable to scientists let alone the general public. :shrug:

 

Following up with some helpful links. >>

NASA's Solar System Exploration: Multimedia: Gallery: Impact Crater Diagram

Simple crater forms are typical of structures with rim diameters of less than about 4 kilometers (on Earth); above this transition diameter, craters are characterized by complex morphologies exhibiting central uplifts, shallow floor depths, and slumped rims.

 

For complex craters with diameters of about 4 to 50 kilometers the central uplift occurs as a single peak. Larger impact structures can have complex, ring-shaped central uplifts.

 

Given that Tortuga Jorge is ~135 kilometers in diameter, the muscon, or central uplift area description as 'complex-ring-shaped' applies nicely. No less the shallow floor depth; undecided on slumped rims?

 

Off to track down a few more resources...:hihi:

Finding Impact Craters -- Diagram

scroll down to see a photomicrograph of shocked minerals that is a slam-dunk ID for impact structures. >> Iowa's Manson Impact Structure

at bottom see rock cores from Chicxulub with shocked minerals. at the top & middle see the kind of setup we need over at Tortuga Jorge. Chicxulubrel.html

[Hill]

You might also be interested in checking out another possible impact in NE Vermont, recently found by one of our newest members. I haven't seen so many probable looking impact sites in a while, including yours. Of course the one I "discovered" in Eretria had been posted 2 years ago, just not noticed. Since I'm still unable to link, you can find the VT one in Nature and Geography forum. I emailed the guys at the Impact Crater Database in Canada and got the following canned response.

"Hines, Jason Thomas" <[email protected]>

to me

 

I will be out of the office until August 21st.

So not much help from that area for another 10 days. It seems you have gotten some responses from those you have tried to contact.

 

Take a look at that one in Vermont; it really looks convincing.

[Turtle]

You might also be interested in checking out another possible impact in NE Vermont, recently found by one of our newest members. I haven't seen so many probable looking impact sites in a while, including yours. Of course the one I "discovered" in Eretria had been posted 2 years ago, just not noticed. Since I'm still unable to link, you can find the VT one in Nature and Geography forum (I know - crummy names :D ) I emailed the guys at the Impact Crater Database in Canada and got the following canned response.

 

So not much help from that area for another 10 days. It seems you have gotten some responses from those you have tried to contact.

 

Take a look at that one in Vermont; it really looks convincing.

 

Roger wilco. here's the link to the thread; KML file is in 2nd post. >> Google Earth Community: Impact Crater in Vermont?

[Hill]

Roger wilco. here's the link to the thread; KML file is in 2nd post. >>

 

Shortly after I sent an "Ask USGS" email, I found this:

 

The Nulhegan Basin was formed when a pool of magma formed within existing metamorphic rock. The magma cooled into a relatively soft granitic rock called quartz monzonite. Once erosion wore away the cap of metamorphic rock, the softer monzonite eroded more rapidly than the surrounding metamorphic rock. This resulted in a relatively flat circular interior area, roughly 10 miles in diameter, surrounded by hills. Sand and gravel were later deposited in the bottom of the Basin by melting glaciers.

Friends of the Nulhegan Basin

 

The Nulhegan Basin would seem to be off the list as a possible impact crater.:D

[Turtle]

I was checkin' out my crater in Chihuahua for the umpteenth time and noticed GE has added some new high-res imagery of the area. It's not complete yet for the entire ~240^2 miles of the feature, but it is much better than the blurry pixelation we had to rely on before. Toward the middle I found what looks like some mining activity perhaps?

 

Anyway, click on the attached KML file below to activate GE and fly to Crater del Tortuga Jorge. B):confused::confused:

[Hill]

I think we should add a link to http://hypography.com/forums/environmental-studies/12843-mystery-meteorite-illness.html since it's a proven new impact with lots of coverage - and more to come I suspect.

[estrar]

The area is known as the copper canyon of chihuahua, here is a photo of the area

 

Also, a few kilometers north there is a recent smaller impact:

 

Google Maps

[freeztar]

National Geographic released this interactive impact crater map that shows major impact sites.

 

Earth Scars - Interactive Map - National Geographic Magazine

[Cedars]

Researching proglacier lakes brought me to this link which is related to Post #7. Some good pics of rocks formed in part by the impact event.

 

For scale, this impact is much larger than the chicxulub impact.

 

Near the end is an estimation of max wind speeds (1400 mph), 1 - 3 meters of ejecta, and earthquakes.

 

http://www.geo.umn.edu/mgs/meteoriteimpact.pdf

[freeztar]

Cool article.

 

Near the end is an estimation of max wind speeds (1400 mph), 1 - 3 meters of ejecta, and earthquakes.

I don't quite understand their table though.

 

ARRIVAL TIME EFFECT MODERN ANALOG

1. ~13 seconds Fireball 3rd degree burns, trees ignite

2. ~2-3 minutes Earthquakes Richter scale 10.2 at Sudbury,

buildings collapse at Gunflint Lake

3. ~5-10 minutes Airborne ejecta a layer 1-3 meters thick, with

arrives fragments <1 cm in size

4. ~40 minutes Air Blast Maximum wind speeds ~1,400 mph

5. ~1-2 hours Tsunami None of this magnitude

 

Why would an air blast arrive 40 minutes after impact?

[Cedars]

Why would an air blast arrive 40 minutes after impact?

 

Dont know. Maybe the max wasnt sustained and it subsided greatly as it worked away from the impact. At 700 mph it would be around 40 mins. Estimation on the tsunami was 1-2 hours so thats a wave moving between 240 and 480 mph.

 

Big stuff if it was half their estimate.

[freeztar]

Dont know. Maybe the max wasnt sustained and it subsided greatly as it worked away from the impact.

 

Hmm...Maybe it has something to do with the initial shockwave? :confused:

 

Where's that Turtle when you need him? :eek_big:

[Turtle]

Cool article.

 

I don't quite understand their table though.

 

Why would an air blast arrive 40 minutes after impact?

 

Hmm...Maybe it has something to do with the initial shockwave?

 

Where's that Turtle when you need him?

 

where any self respecting turtle should be during an impact; hiding in a hole in the mud. :eek2:

 

i agree the table is confusing without any calculations. 1,400 mph would reach 466.6 miles in 20 minutes and the distance between impact and the Gunflint site is given as 480 miles. :shrug:

 

Researching proglacier lakes brought me to this link which is related to Post #7. Some good pics of rocks formed in part by the impact event.

 

For scale, this impact is much larger than the chicxulub impact.

 

Near the end is an estimation of max wind speeds (1400 mph), 1 - 3 meters of ejecta, and earthquakes.

 

http://www.geo.umn.edu/mgs/meteoriteimpact.pdf

 

the article has a promotional slant for the region, but nonetheless, a very cool impact and article. thanks Cedars. :) here's some reading on the physics of space rock impacts: >> Impact Geology, Chemistry and Physics

the game is afoot. :eek: ;)

[Cedars]

where any self respecting turtle should be during an impact; hiding in a hole in the mud. :eek2:

 

i agree the table is confusing without any calculations. 1,400 mph would reach 466.6 miles in 20 minutes and the distance between impact and the Gunflint site is given as 480 miles. B)

Looking back over the article, they used a computer program to calculate whatever:

"Collins, G.S., Melosh, J. H., Marcus, R.A., 2005, Earth impact effects

program: A web-based computer program for calculating the

regional environmental consequences of a meteoroid impact on

Earth; Meteorite and Planetary Science 40:817-840."