Quake Watch 2011

Originally posted by PuterMan
reply to post by boo1981

 

No, I believe it was actually an earthquake this time.

Rattled the teacups of the old ladies of Worthing!

Thanks for the conformation PM
And there is another one also!

ENGLISH CHANNEL
July 14, 2011
Time: 13:30:50.6
Lat./Lon.: 50.113 -0.727
National Grid: 491.0 km E, 24.5 km N
Depth: 10.0
Magnitude: 1.8

BGS

Looks like here is some activity that has not been posted on USGS. Any one have any ideas??

Seems as though activity around the globe is picking back up again. This link is from the USGS website, but no earthquakes have been posted in Virginia.

USGS Website Link to Webicorders

reply to post by MountainEnigma


Most likely that siesmo is picking up the activity in Puerto Rico

Buoy activity on both sides of US now.
National Data Bouy Center link

reply to post by LexiconV


I have never looked at that.. What does it mean "Tsunami station in event mode" because thats what those two stations are doing,,

Originally posted by LexiconV
Buoy activity on both sides of US now.
National Data Bouy Center link

Excuse my ignorance Lexicon, I have never seen that particular map before....what exactly does that indicate?

reply to post by berkeleygal


Can you explain briefly how it would be picking up seismos from Puerto Rico when it is an inland recorder, the other recorders in the area are not showing activity or different activity, and it is so far away from Puerto Rico?? I would think that SC and GA would show first.

Please clarify if you can. Thanks.

reply to post by MountainEnigma


It was just a guess..

2nd

Its a live monitoring system for global tsunami events caused by above/underwater landslides and thrusts. Yellow has recent activity, click on to see stats. There are different styles of recorded info eg... Water Temp, Air Temp, Atmospheric Pressure, Wind, Significant Wave Height and Dominant Wave Period. Very useful for weather prediction and navigating the oceans safety for ships.
At times the sea bed will drop without a seismic event recorded as an earthquake. It can be an underwater landslide which displaces huge amounts of water that causes a Tsunami and not necessarily a quake. Either way, its through this site that a variety of buoys throughout the world are monitored collectively.

Each DART® station consists of a surface buoy and a seafloor bottom pressure recording (BPR) package that detects pressure changes caused by tsunamis. The surface buoy receives transmitted information from the BPR via an acoustic link and then transmits data to a satellite, which retransmits the data to ground stations for immediate dissemination to NOAA's Tsunami Warning Centers, NOAA's National Data Buoy Center, and NOAA's Pacific Marine Environmental Laboratory. The Iridium commercial satellite phone network is used for communication between 31 of the buoys.[2] When on-board software identifies a possible tsunami, the station leaves standard mode and begins transmitting in event mode. In standard mode, the station reports water temperature and pressure (which are converted to sea-surface height) every 15 minutes. At the start of event mode, the buoy reports measurements every 15 seconds for several minutes, followed by 1-minute averages for 4 hours.[3] The first-generation DART I stations had one-way communication ability, and relied solely on the software's ability to detect a tsunami to trigger event mode and rapid data transmission. In order to avoid false positives, the detection threshold was set relatively high, presenting the possibility that a tsunami with a low amplitude could fail to trigger the station. The second-generation DART II is equipped for two-way communication, allowing tsunami forecasters to place the station in event mode in anticipation of a tsunami's arrival.

See here for pictures and further info on DART


As you know.... there is the Juan de Fuca Plate under the west side buoy that is currently active. As none of the other buoys directly near were effected it was probably a landslide, same on the west coast.
There was a minor earthquake yesterday in the English channel and a minor tsunami last week from a possible underwater landslide as no quakes were recorded at the time. The African plate is diving under the European plate hence seismic activity in Europe.

A few days ago the buoy on the west coast of Australia went into event mode, they've had several quakes in Western Australia and its been rather seismically active across the continent/island over the last 20 days.. The Australian plate buckles as it rises on the east and sinks towards the north west under Indonesia.

reply to post by LexiconV


Thank you for that explanation, I appreciate it. Sooo, basically there can be a tsunami with out prior earthquake??..Or am I confused? Or could the site you shared show some thing happening prior to a possible earthquake? Just want to make sure I am following correctly - sorry

reply to post by summer5


Yep... landslides often don't register as a seismic event but can still cause a tsunami. As one area is unloaded it may cause a pressure release or earthquake elsewhere nearby. Earthquakes as such don't cause tsunamis but mega thrusts, landslides, volcanic flankslides and asteroids do. There have been several fresh water tsunamis from landslides within dams too Vajont Dam and coastal Lituya Bay.

From the past Evidence of Hawaiian Island flank collapse and tsunami
Possible future event Cumbre Vieja Volcano

reply to post by LexiconV

Well I just learned some thing new! Thank you, I had no idea

Originally posted by summer5
reply to post by LexiconV

 

Well I just learned some thing new! Thank you, I had no idea

You're welcome... I come here to learn also. I've picked up many useful sites for gathering info and knowledge on this forum. Notice I distinguish between info and knowledge...

A lot of activity around the Virgin Island. Multiple quakes within minutes and hours of each other.

USGS

Here is a better view of all of them around Virgin Islands. Zoom on down toward Puerto Rico/Virgin Islands and you will notice a cluster.
RSOE

Another source. 20 quakes. All around an average of 3's.

EFG-BN

And another one!

ENGLISH CHANNEL
July 14, 2011
Time: 20:55:09.1
Lat./Lon.: 50.078 -0.600
National Grid: 500.2 km E, 20.8 km N
Depth: 10.0
Magnitude: 1.8

So this makes three now!
Here are the other two:

ENGLISH CHANNEL
July 14, 2011
Time: 13:30:50.6
Lat./Lon.: 50.113 -0.727
National Grid: 491.0 km E, 24.5 km N
Depth: 10.0
Magnitude: 1.8

ENGLISH CHANNEL
July 14, 2011
Time: 06:59:10.9
Lat./Lon.: 50.122 -0.743
National Grid: 489.8 km E, 25.5 km N
Depth: 10.0
Magnitude: 3.9
Intensity: 3
FELT S COAST ENGLAND

BGS

All at the same depth of 10km.

reply to post by berkeleygal


The Bermuda one looks like a glitch. No data since 02:00

There are often data problems with these, like the one off Australia that has in the past on 2 occasions that I am aware of registered a change in the sea floor bed of around 5000ft. ( I say sea floor bed because obviously the sea level did not change that much! )

Taupo 6.5 ten days ago
I missed this when it came out 9 days ago.
Basically covers the current theory on subduction.
Explains;
Why the quake was felt to the SE
Why no aftershocks ( in fact there were 2 x Mag 3 at about the same depth, see my 30 day NZ Map)
Stress triggering "Earthquake occurrence is random on a global scale"

Canterbury region long-term probabilities

Dates - Probability magnitude 5.0 - 5.9 - Probability greater than 6.0

• Jul 15 2011- Jul 14 2012 - a 9 in 10 chance - a 1 in 4 chance
  
• Aug 15 2011 - Aug 14 2012 - a 9 in 10 chance - a 1 in 5 chance
  
• Sep 15 2011 - Sep 14 2012 - a 9 in 10 chance - a 1 in 5 chance
  

This table was last updated on July 14 2011

www.geonet.org.nz...

Lincoln/ Halswell Fault - The Gap

A network of hidden faults on the outskirts of Christchurch will be the focus of more research to ascertain their earthquake risk.

Seismic surveying by Canterbury University and Calgary University researchers has revealed 10 previously unknown faults west and southwest of the city, including one running from near Lincoln to Halswell.

The survey work is looking at the area between the ends of the Greendale and Port Hills faults, known as "the gap".

At a briefing yesterday, GNS Science natural hazards platform manager Kelvin Berryman said a 30 kilometre line had been surveyed from north of Lincoln across State Highway 1 near Weedons to State Highway 73 just east of West Melton

A cross-section of rocks and sediment to about 1.5km underground showed five faults between about Lincoln and Weedons extending to within about a hundred metres of the surface.

Between there and West Melton there was also evidence of five very old faults in rocks below about 1km, he said.

The surveying had shown there was no obvious connection between the Greendale and Port Hills faults, although the Greendale Fault might extend further east than previously thought.

"There's lots of question marks still. It's complicated down there. There's multiple hidden fault structures."

A fault running from west of Lincoln to northwest of Halswell ran through the "gap" and separated the two other faults.

The magnitude-5.4 earthquake on June 21, centred near Halswell and Prebbleton, was the strongest locally felt earthquake of the 10-month series.

With ground accelerations of up to 60 per cent of gravity, it was felt more sharply than the September 4 magnitude-7.1 shock, Berryman said.

"In the Halswell-Lincoln zone so far, the total amount of energy released on that [fault] is less than that of a magnitude-6.0 earthquake, so that could be one of the candidates if there were to be another magnitude-6.0-plus earthquake.

"We need to be careful and cautious.

"This is quite preliminary. There's no evidence of these things at the surface. It may have done its dash, but there's still a lot of activity going on over there," Berryman said.

"That is a good place to keep working for a few months."

The Boxing Day quake, generated by a small fault under the northern central business district, was still a mystery, he said.

"There has been no further activity on that, which I'm guessing is a really good sign."

The June 13 quake appeared to have been produced by a six to eight-kilometre fault roughly parallel to the coast from north of New Brighton to the Avon-Heathcote Estuary and possibly further south.

www.stuff.co.nz...

reply to post by berkeleygal


Is glitch. The web site still says 0200 but in Google Earth I get up to 1800

The Google Earth version does not have the red writing.