Magnitude 3.5 - OFFSHORE ALABAMA

[Guest guest]

http://earthquake.usgs.gov/earthquakes/recenteqsus/Quakes/us2011hmbx.php

Magnitude 3.5 - OFFSHORE ALABAMA

Magnitude 3.5

Date-Time Friday, February 18, 2011 at 23:15:34 UTC

Friday, February 18, 2011 at 05:15:34 PM at epicenter

Time of Earthquake in other Time Zones

Location 30.180°N, 87.848°W

Depth 5 km (3.1 miles) set by location program

Region OFFSHORE ALABAMA

Distances 60 km (35 miles) SSE of Mobile, Alabama

65 km (40 miles) WSW of Pensacola, Florida

70 km (45 miles) ESE of Pascagoula, Mississippi

285 km (175 miles) SSW of MONTGOMERY, Alabama

Location Uncertainty horizontal +/- 15 km (9.3 miles); depth fixed by location

program

Parameters NST= 25, Nph= 25, Dmin=326.9 km, Rmss=1.33 sec, Gp=176°,

M-type= " Nuttli " surface wave magnitude (mbLg), Version=6

Source USGS NEIC (WDCS-D)

Event ID us2011hmbx

[Guest guest]

A couple of things to notice here.

First on this link, you should see the location of the quake marked. Just to the south in the water you can see a thing that looks like a river channel. It isn't.

http://maps.google.com/maps?q=30.1802+-87.8476(M3.5+-+OFFSHORE+ALABAMA+-+2011+February+18++23:15:34+UTC) & f=d & t=h & hl=e & ie=UTF8 & ll=30.206861,-87.643433 & spn=0.701402,0.861053 & z=10

Remember where that channel connects with the shore line and look at this map screen.

http://maps.google.com/maps?q=30.1802+-87.8476(M3.5+-+OFFSHORE+ALABAMA+-+2011+February+18++23:15:34+UTC) & f=d & t=h & hl=e & ie=UTF8 & ll=33.449777,-82.749023 & spn=10.824731,13.776855 & z=6

Look at that map going northeast along I-65 then over to Columbia, just north of Macon, just north of Augusta and on to Charlotte and Raleigh. You'll see that's a darker green valley. That's the fall line. It also runs from Raleigh through Richmond, near DC and a ways further north. This is actually a fault line. It is the one that caused several quakes around magnitude 4 in the last 10 years or so. The Alabama end seems to be the end of it, but then I'm not sure if it has been tracked into the Gulf.

In a message dated 2/20/2011 10:47:36 A.M. Eastern Standard Time, no_reply writes:

Magnitude 3.5 - OFFSHORE ALABAMA

[Guest guest]

Thanks Interesting!Cynically I wonder how many people who live in those areas are even aware of the fault line?rl'My cat Rusty is a servant of the Living God....'adapted from a poem by SmartSubject: Re: Magnitude 3.5 - OFFSHORE ALABAMATo: FAMSecretSociety Received: Sunday, February 20, 2011, 12:37 PM

A couple of things to notice here.

First on this link, you should see the location of the quake marked. Just to the south in the water you can see a thing that looks like a river channel. It isn't.

http://maps.google.com/maps?q=30.1802+-87.8476(M3.5+-+OFFSHORE+ALABAMA+-+2011+February+18++23:15:34+UTC) & f=d & t=h & hl=e & ie=UTF8 & ll=30.206861,-87.643433 & spn=0.701402,0.861053 & z=10

Remember where that channel connects with the shore line and look at this map screen.

http://maps.google.com/maps?q=30.1802+-87.8476(M3.5+-+OFFSHORE+ALABAMA+-+2011+February+18++23:15:34+UTC) & f=d & t=h & hl=e & ie=UTF8 & ll=33.449777,-82.749023 & spn=10.824731,13.776855 & z=6

Look at that map going northeast along I-65 then over to Columbia, just north of Macon, just north of Augusta and on to Charlotte and Raleigh. You'll see that's a darker green valley. That's the fall line. It also runs from Raleigh through Richmond, near DC and a ways further north. This is actually a fault line. It is the one that caused several quakes around magnitude 4 in the last 10 years or so. The Alabama end seems to be the end of it, but then I'm not sure if it has been tracked into the Gulf.

I

[Guest guest]

" Cynically I wonder how many people who live in those areas are even aware of

the fault line? "

My guess is zero. No one in St. Louis seems to be worried about another New

Madrid quake. Few people in California care about the San Adreas...and those

people KNOW about those faults.

I doubt people who live near less active fault lines know that they are living

near them.

Administrator

[Guest guest]

Its not quite zero, but the knowledge isn't common. Most people don't even understand what the fall line is even though it is very visible in many places, mainly along rivers. Even fewer realize it is an active fault. We get quakes large enough to feel every few years, but most people either don't pay attention or quickly forget all about it.

Note: The following links say Offshore Alabama, but they are correct for what where I have placed them. It is just that I linked from that original Alabama search.

Here is the fall line in Richmond, Virginia. To the west (left) of the 360/S 14th street bridge you can see rapids. To the east (right) is the tidal portion of the River.

http://maps.google.com/maps?q=30.1802+-87.8476(M3.5+-+OFFSHORE+ALABAMA+-+2011+February+18++23:15:34+UTC) & f=d & t=h & hl=e & ie=UTF8 & ll=37.527426,-77.435396 & spn=0.010091,0.013454 & z=16

Here is a streetview link on that bridge. You can see the rapids well. The other direction is on the tidal section though it looks into the sun. Getting a streetview from the I-95 bridge is clearer for the tidal part.

http://maps.google.com/maps?q=30.1802+-87.8476(M3.5+-+OFFSHORE+ALABAMA+-+2011+February+18++23:15:34+UTC) & f=d & t=h & hl=e & ie=UTF8 & ll=37.528353,-77.4344 & spn=0,0.006727 & z=17 & layer=c & cbll=37.528353,-77.4344 & panoid=5wJU0oeBE2fShMSdFVPIPg & cbp=12,285.34,,0,16.05

And a link to a panorama of the rocky part of the river.

http://maps.google.com/maps?q=30.1802+-87.8476(M3.5+-+OFFSHORE+ALABAMA+-+2011+February+18++23:15:34+UTC) & f=d & t=h & hl=e & ie=UTF8 & ll=37.527468,-77.436029 & spn=0,0.006727 & z=17 & layer=c & cbll=37.527511,-77.436061 & cbp=12,0,,0,5 & photoid=po-41506245

Here is the fall line in sburg, Virginia. Its a little obscured because of a couple of small dams, but it is approximately where Chesterfield Avenue crossed the Appomattox River. You can't really tell from this shot but it is very rocky to the left of the bridge. Incidentally, to the right of the bridge there used to be an elevated railroad track. You can still see the pillars if you zoom in enough. They too are much taller than they look. Kids used to jump from it long ago, so that tells you have quickly the land went from shallow rapids to deep tidal waters. But then its hard to tell just where the fall line is for the small dams.

http://maps.google.com/maps?q=30.1802+-87.8476(M3.5+-+OFFSHORE+ALABAMA+-+2011+February+18++23:15:34+UTC) & f=d & t=h & hl=e & ie=UTF8 & ll=37.232174,-77.416856 & spn=0.010131,0.013454 & z=16

Here is a street view. It starts facing upstream toward the fall line. Turn around to see the bridge pillars and toward the tidal section.

http://maps.google.com/maps?q=30.1802+-87.8476(M3.5+-+OFFSHORE+ALABAMA+-+2011+February+18++23:15:34+UTC) & f=d & t=h & hl=e & ie=UTF8 & ll=37.232464,-77.41735 & spn=0,0.013454 & z=16 & layer=c & cbll=37.232527,-77.417395 & panoid=N8pv7oznq2kx41f1GVowKQ & cbp=12,248.36,,0,8.3

In a message dated 2/20/2011 5:10:38 P.M. Eastern Standard Time, no_reply writes:

My guess is zero. No one in St. Louis seems to be worried about another New Madrid quake. Few people in California care about the San Adreas...and those people KNOW about those faults.I doubt people who live near less active fault lines know that they are living near them.Administrator