Craters on Earth and the other Planets

[Harry Costas]

Hello All

 

We sometimes look beyond our earth and miss important observations at our door steps.

 

Impact Cratering

 

http://www.lpi.usra.edu/education/explore/shaping_the_planets/impact_cratering.shtml

 

 

 

Earth impact data base

 

http://www.unb.ca/passc/ImpactDatabase/austr.html

 

 

It is amazing that we notice so many craters on the moon and other planets and not notice as much on earth.

[Jay-qu]

partly due to the fact that earth doesnt have nearly as many impacts as the moon due to our atmosphere.. and also the fact that our crust recycles itself, things get eroded and dissapear on earth, while on the moon they lay mostly undisturbed in the regolith.

[Harry Costas]

Hello Jay

 

Thats correct.

 

But the links are very educational in that it shows the location of these craters as they are found world wide.

 

Your right erosion and plate movements have hidden and changed their forms.

[Turtle]

Hello All

 

We sometimes look beyond our earth and miss important observations at our door steps.

 

Impact Cratering

 

We can thank satellite technology for many of the impact crater discoveries. The most recent were found by amateurs using Google Earth as I recall.

http://www.astroseti.org/impacts.php

Your implication of some kind of malfeasance is akin to blaming a blind umpire for a bad call. :) :)

[Harry Costas]

Hello Turtle

 

 

Thanks for the link.

[Turtle]

Hello Turtle

 

 

Thanks for the link.

 

De nada. Check this new discovery!

 

Most astronomers doubt that any large comets or asteroids have crashed into the Earth in the last 10,000 years. But the self-described “band of misfits” that make up the two-year-old Holocene Impact Working Group say that astronomers simply have not known how or where to look for evidence of such impacts along the world’s shorelines and in the deep ocean.

 

Scientists in the working group say the evidence for such impacts during the last 10,000 years, known as the Holocene epoch, is strong enough to overturn current estimates of how often the Earth suffers a violent impact on the order of a 10-megaton explosion. Instead of once in 500,000 to one million years, as astronomers now calculate, catastrophic impacts could happen every few thousand years.

http://www.nytimes.com/2006/11/14/science/14WAVE.html?_r=1&ref=science&oref=slogin

[Jay-qu]

"heads up!" :(

[Tormod]

"Every few thousand years"...great one, Turtle.

[Turtle]

"Every few thousand years"...great one, Turtle.

 

Eh oh! You have just prompted me to some purely wild speculation. :fly: What if, given the apparent frequency of Earth-impacting space-rocks, supervolcanoes originated with large impacts‽

[Harry Costas]

Hello Turtle

 

Good point.

 

In my opinion history shows super volcanoes orginate from plate movements.

 

But! you never know, if you never ever go with some new ideas.

[Turtle]

Hello Turtle

 

Good point.

 

In my opinion history shows super volcanoes orginate from plate movements.

 

But! you never know, if you never ever go with some new ideas.

Hi Harry,

My only point of contention comes by way of counter-example. Yellowstone caldera is well within the North American plate and nowhere near a boundary, rather it derives from a 'hot spot' (the technical term for a magma plume not at a plate boundary) the origins and mechanics of which is yet little understood. It is this mystery of the origin of 'hot spots that my conjecture is directed at, that is to say they originated with an impact from a space-rock. To extend that speculation, the current situation of hot spots is as a deep wound in flesh, which periodically opens and festers.

 

Or not.:cup:

[Harry Costas]

Hello Turtle

 

Hot spots are created by plate movements creating convectional currents that pop up as hot spots. The hawaii islans are a prime example. String of islands heading towards Japan. Once the islands pass the hot spot they are no longer active.

 

The lava that comes out from the volcanoes has properties of the sea bed.

The oceanic plate meets the continental plate creating an oceanic trench some 40,000 feet or so. the plates meet and fold down. Oceanic plates are thinner and so rotate quicker under creating a convectional current that pops up. Because of this oceanic plates are only a few hundred years old, because they recycle.

 

 

If you need more explanation, just let me know.

 

I did this subject many years ago at uni.

[Turtle]

Hello Turtle

 

Hot spots are created by plate movements creating convectional currents that pop up as hot spots. The hawaii islans are a prime example. String of islands heading towards Japan. Once the islands pass the hot spot they are no longer active.

 

The lava that comes out from the volcanoes has properties of the sea bed.

The oceanic plate meets the continental plate creating an oceanic trench some 40,000 feet or so. the plates meet and fold down. Oceanic plates are thinner and so rotate quicker under creating a convectional current that pops up. Because of this oceanic plates are only a few hundred years old, because they recycle.

 

 

If you need more explanation, just let me know.

 

I did this subject many years ago at uni.

Hi Harry,

Yes, your description sounds many years old. Point of fact, the Hawaiian islands do have their source in a hot spot, however they/it is in the middle of the Pacific plate and again not at a plate boundary. If I require more misinformation, I'll contact you.:doh:

[Turtle]

Hello Turtle

Oceanic plates are thinner and so rotate quicker under creating a convectional current that pops up. Because of this oceanic plates are only a few hundred years old, because they recycle.

 

 

If you need more explanation, just let me know.

 

I did this subject many years ago at uni.

 

Hi again Harry,

Just back to correct some specific misinformation you proffered. I have boldened the pertinent error and have this link for you (et al) to study.

http://www.geosci.usyd.edu.au/research/marinegeophysics/Resprojects/Agegrid/Images/crustageposter.gif

:shade:

[Harry Costas]

Hello Turtle

 

You said

 

Yes, your description sounds many years old. Point of fact, the Hawaiian islands do have their source in a hot spot, however they/it is in the middle of the Pacific plate and again not at a plate boundary. If I require more misinformation, I'll contact you.

 

Yes I agree with you.

 

You have miss understood what I said.

 

Next time get the explanation understood.

 

Many years old. What a cope out.

 

 

In either case look up the info. Its general info.

[Turtle]

Hello Turtle

 

You have miss understood what I said.

I don't think so. :)

 

Next time get the explanation understood.

See above.

 

Many years old. What a cope out.

I think you meant 'cop out'. My comment was a jockular barb at your touting your education while making misstatements of fact. Rather than copping

out I followed my jest with correction to those misstatements.

 

In either case look up the info. Its general info.

The information is specific and you have misrepresented it; I note you didn't challenge my correction of your claim for a 400 year recycle period.

 

Meantime the discovery of previously unknown cratering events on Earth, the planets, and their satellites continues to add to our understanding of geologic processes. ;)

 

Post Script: Hypography Science News Article:

http://hypography.com/forums/general-science-news/6918-killer-crater-found-under-ice-antarctica.html

[Harry Costas]

Hello Turtle

 

I know the Hawaii islands are not on the boundry of plates. They are at a hot spot created by convectional currents created by the movement of the oceanic plate folding down and under. This convectional current takes oceanic floor material withit and realeasing it via the volcanoes.

 

Making silly comments does not make you right.

 

I'm here to discuss issues not to go into some form of silly conflict of words.

 

Old ideas,,,,,,,,,,,very funny