http://www.ashdodsurf.com/earthquake-zones/
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earthquake zones
What is the relationship among the distribution of volcanoes,plate boundaries, and earthquake zones?
Its dealing with the tectonic plates thats all I know
Most volcanoes and earthquakes are found along plate boundaries.
Constructive - Shallow earthquakes,volcanoes (forming island,guyots,sea mounts etc.)
Destructive - Shallow earthquakes, volcanoes
Transform - Major earthquakes (think about San Francisco and the San Andreas Fault)
Collision - No volcanoes and some earthquakes, but mainly orogeny (uplift and mountain building)
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Las Vegas Earthquake Map Shows Greatest Risk
Higher risk earthquake zones in mid plate?
I hate it when National Geographic Magazine contains a map with interesting information not explained on the map or within the accompanying article. Such in the recent April issue, vis a vis earthquakes. The map indicates larger mid-plate areas of higher occurance and risk for more major earthquakes include much of central and western Australia and surrounding the St Lawrence River Valley and smaller areas in west-central Africa, northeastern Brazil and a few other places, including of course the New Madrid area. Nothing in the article explains the geologic whys for these areas being comparatively more severe earthquake prone. Fortunately a couple of professional geologists' answers to other Yahoo Answers queries detail about the reasons for New Madrid (thank you) but what about the others, especially Austraila's and the St-Lawrence?
I think the answer to your question, that all of these places seem to have in common is: they are failed rift zones.
The New Madrid Fault is a failed rift zone, as is the Amadeus Basin in Australia. West-central Africa is the Great Rift Basin, connected to the Red Sea, which is one arm of that rift that is not a failed rift zone. Northeastern Brazil is another failed rift zone. The St. Lawrence River is another.
http://earthquakescanada.nrcan.gc.ca/zones/eastcan_e.php#LSLSZ
A rift zone is an area of the earth's crust that is being pulled apart by plate tectonic forces. In many instances these rift zones form a three-armed triple junction. As two of these arms dominate, the third arm becomes the failed rift arm. The New Madrid Fault zone is believed to be one of these failed rift arms from the rifting that separated South America from North America during the breakup of Rodinia. Actually the Rio Grande is a failed rift zone as well.
http://home.att.net/~sgeoveatch/rio_grande_rift.htm
The East African Rift Valley (the Great Rift Valley) is the failed arm where Africa is moving away from Asia and Saudi Arabia. Here is a USGS diagram of the Great Rift Basin in Africa:
http://pubs.usgs.gov/gip/dynamic/East_Africa.html
Australia's Amadeus basin is a failed rift that formed duing the breakup of Rodinia, an ancient supercontinent.
http://www.ga.gov.au/oceans/ea_Amadeus.jsp
Each of these rift arms represents a thinned and broken, faulted part of the continental crust that can be reactivated over time and will act as a weak point when either compressive or extensional plate tectonic forces are applied to a continent. Thus the likelihood of earthquakes.
4 Comments
As an intelligent outsider, I take fault zone to mean that there is a concentration of faults that are not linked while a fault system is a pattern of related faults. For example, the faults in a valley might be from scrunching the area due to plate movement and subduction while a fault system might be a rectangle around a fault block or a series marking the border of a plate in slip movement. You can have a zone before you have done enough research to prove the faults in the zone are part of a system.
Ok, this is my “wrap-up” post, before disappearing again as promised in previous thread. See also the two external links from that comment for a “mainstream” version of my general position.
“Satan puts his interpretation upon events, and they (the people) think, as he would have them, that the calamities which fill the land are a result of Sunday-breaking. Thinking to appease the wrath of God, these influential men make laws enforcing Sunday observance” (1888)
Sunday enforcement will follow a false religious revival, it is the mark of the beast (the catholic church) and those who keep God's true Sabbath will be persecuted and killed
The North Anatolian Fault is one of the most energetic earthquake zones in the world where Turkey lies. #Turkey #earthquake #beprepared