[Rockhounds] Difference between East and West Coast US
earthquakes, was New Madrid fault
Kreigh Tomaszewski
Kreigh at Tomaszewski.net
Fri Mar 27 18:44:16 PDT 2009
Kris,
That is a good analogy. It would be even better if the tub of balls
also included ping pong balls, marbles, ball bearings, baseballs,
lacrosse balls, nurf balls, and hockey pucks. The western US really is
a huge mix of accumulated geology.
Kreigh
On Friday, Mar 27, 2009, at 16:58 America/Detroit, Kris Rowe wrote:
> Carol, by way of analogy, would it be accurate to compare this to the
> difference in transferred vibration between a tub of golf balls, and a
> tub
> of solidified plaster?
> What I mean is, by way of example, hitting one end of each tub with a
> drumstick and measuring the vibrations intensity as it reaches the
> other end
> of the tub. Of course, the plaster ( the Eastern U.S.) would be a far
> more
> efficient conductor of vibration than the golf balls (the Western
> U.S.),
> wouldn't it?
>
> As they taught us back in Recording Engineering school, a contiguous
> solid
> always transmits vibration more efficiently than a broken solid. i
> know this
> is a bit simplistic, but should apply, more or less.
>
> Thanks,
> Kris
>
> On Fri, Mar 27, 2009 at 10:40 AM, J Bryan Kramer
> <codeburner at gmail.com>wrote:
>
>> That's interesting, of course the west was created by a series of
>> island
>> chains crashing into the western coastline. That created the Basin and
>> Range
>> topography and of course fractured the rock and created all those
>> faults.
>> McPhee has a good book about it called, no surprise, Basin and Range
>>
>> <
>>
>> http://www.amazon.com/Basin-Range-John-McPhee/dp/0374516901/
>> ref=pd_bbs_sr_1?ie=UTF8&s=books&qid=1238175482&sr=8-1
>>>
>>
>> But it's better to get it in his compilation Annals of the Former
>> World
>>
>> <
>>
>> http://www.amazon.com/Annals-Former-World-John-McPhee/dp/0374518734/
>> ref=pd_bbs_2?ie=UTF8&s=books&qid=1238175482&sr=8-2
>>>
>>
>> BK
>>
>> On Fri, Mar 27, 2009 at 10:57, Carol J. Bova <bova at mindspring.com>
>> wrote:
>>
>>> Dora,
>>> It's not that scientists can't deal with dynamic complexity, it's
>>> that
>>> there is a major difference between California and the East Coast
>>> when it
>>> comes to earthquakes:
>>>
>>> "East Coast earthquakes, such as the one that struck Charleston,
>>> South
>>> Carolina, in 1886 are felt over a much larger area than earthquakes
>>> occurring on the West Coast, because the eastern half of the country
>>> is
>>> mainly composed of older rock that has not been fractured and
>>> cracked by
>>> frequent earthquake activity in the recent geologic past. Rock that
>>> is
>>> highly fractured and crushed absorbs more seismic energy than rock
>>> that
>> is
>>> less fractured. The Charleston earthquake, with an estimated
>>> magnitude of
>>> about 7.0, was felt as far away as Chicago, more than 1,300 km to the
>>> northwest, whereas the 7.1-magnitude Loma Prieta earthquakes was
>>> felt no
>>> farther than Los Angeles, about 500 km south. The most widely felt
>>> earthquakes ever to strike the United States were centered near the
>>> town
>> of
>>> New Madrid, Missouri, in 1811 and 1812. Three earthquakes, felt as
>>> far
>> away
>>> as Washington D.C., were each estimated to be above 8.0 in magnitude.
>> Most
>>> of us do not associate earthquakes with New York City, but beneath
>> Manhattan
>>> is a network of intersecting faults, a few of which are capable of
>> causing
>>> earthquakes. The most recent earthquake to strike New York City
>>> occurred
>> in
>>> 1985 and measured 4.0 in magnitude, and a pair of earthquakes
>>> (magnitude
>> 4.0
>>> and 4.5) shook Reading, Pennsylvania, in January 1994 causing minor
>> damage."
>>> From: USGS, This Dynamic Earth, Plate Tectonics and People
>>> http://pubs.usgs.gov/gip/dynamic/tectonics.html
>>>
>>> ((Side note: I had just moved to Brooklyn in 1985, and the night
>>> before
>> our
>>> furniture arrived, was sleeping on the floor in a sleeping bag when
>>> the
>>> quake on the Hudson Valley fault hit. It felt like someone shaking
>>> me,
>> and
>>> it wasn't until I sat up and realized my husband was still asleep,
>>> and
>>> another tremor shook us that I realized I was experiencing my first
>>> earthquake.))
>>>
>>> Check out this database:
>>> U.S. Geological Survey and New Mexico Bureau of Mines and Mineral
>>> Resources, 2006,
>>> Quaternary fault and fold database for the United States, accessed
>>> Jan 9,
>>> 2006, from USGS web site:
>>> http//earthquake.usgs.gov/regional/qfaults/
>>>
>>> It is so full of information and links and maps, you could spend a
>>> year
>> in
>>> it!
>>> Carol
>>>
>>>
>>>
>>> On Mar 27, 2009, at 10:55 AM, Dora Smith wrote:
>>>
>>> Thanks! Good article! I will add it to my page.
>>>>
>>>> It looks like the scientists workign on the fault really can't deal
>>>> with
>>>> dynamic complexity; it's a problem shared by alot of scientists.
>>>>
>>>> Rules that apply to the California faults don't apply to the New
>>>> Madrid
>>>> fault system? Come on!
>>>> Yours,
>>>> Dora Smith
>>>> Austin, TX
>>>> tiggernut24 at yahoo.com
>>>>
>>>
>>> ----- Original Message ----- From: <betdav97 at aol.com>
>>>> To: <rockhounds at lists.drizzle.com>
>>>> Sent: Thursday, March 26, 2009 12:30 PM
>>>> Subject: Re: [Rockhounds] New Madrid fault
>>>>
>>>> Except for the first few posts, I have not been following this
>>>>> thread, but this just came across the net, hope it hasn't been
>>>>> posted already.
>>>>>
>>>>> http://news.aol.com/article/new-madrid-fault/398744
>>>>>
>>>>>
>>>
>>> --- StripMime Report -- processed MIME parts ---
>>> multipart/alternative
>>> text/plain (text body -- kept)
>>> text/html
>>> ---
>>> --
>>> _______________________________________________
>>> Rockhounds at drizzle Mailing List
>>> Subscription Services:
>>> http://lists.drizzle.com/mailman/listinfo/rockhounds
>>> List Home Page, with a link to the List Usage Policy:
>>> http://www.eclecticlapidary.com/Rockhounds/index.html
>>>
>>
>>
>>
>> --
>> “It often seems to me that the night is much more alive and richly
>> colored
>> than the day."
>>
>> Vincent van Gogh
>>
>> J Bryan Krämer North Florida, USA
>> photos at: http://pbase.com/photoburner
>> blog at: http://www.photoburner.net
>>
>>
>> --- StripMime Report -- processed MIME parts ---
>> multipart/alternative
>> text/plain (text body -- kept)
>> text/html
>> ---
>> --
>> _______________________________________________
>> Rockhounds at drizzle Mailing List
>> Subscription Services:
>> http://lists.drizzle.com/mailman/listinfo/rockhounds
>> List Home Page, with a link to the List Usage Policy:
>> http://www.eclecticlapidary.com/Rockhounds/index.html
>>
>
>
> --- StripMime Report -- processed MIME parts ---
> multipart/alternative
> text/plain (text body -- kept)
> text/html
> ---
> --
> _______________________________________________
> Rockhounds at drizzle Mailing List
> Subscription Services:
> http://lists.drizzle.com/mailman/listinfo/rockhounds
> List Home Page, with a link to the List Usage Policy:
> http://www.eclecticlapidary.com/Rockhounds/index.html
>
More information about the Rockhounds
mailing list