A USGS scientist said he has never seen tremors as the type that are occurring by the sinkhole.
Portions: (more at link above)
Steve Horton, research scientist with the University of Memphis Center for Earthquake Research and Information
Horton sits on a scientific advisory committee that the Louisiana Department of Natural Resources formed to study the sinkhole, the tremors and natural gas releases that are also occurring in area bayous.
On a seismometer, the sharp tremors are recorded as having one back-and-forth oscillation in less than a second — multiple oscillations are bunched together like scribble-scratch on a graphical depiction — and the tremors last no more than a minute.
In contrast, on a seismometer, the long-period tremors are recorded as having one back-and-forth oscillation over 20 to 40 seconds — the wave pattern is easily distinguishable on a graph — and the tremors last for three to four minutes.
Horton said he has never seen such a combination of tremors before from the same area at the same time.
“Yes, it does lead to a lot of questions and that’s really where we are,” he said. “We have a lot of questions as to what’s going on and not a lot answers.”
He said the long-period tremors could be related to something connected with natural gas, but he cautioned that was speculation.
“There is something going on with these very long-period signals, and we don’t know what it is … I haven’t figured it out yet,” Horton said.
The Assumption website has these updates from yesterday. They said the drilling has stopped due to the drill hitting a Natural Gas pocket at only 90 feet under.
Drilling of the sonic rig that encountered gas at 90’ on Friday was stopped and plugged with cement and grout as they were unable to put in the water well due to the inability to control the gas pushing mud and water to the surface. DNR hired The Shaw Group engineers to redesign a well that can be placed for venting operations. The geo-probe rigs for observation continue to be placed at lower depths to check for the presence of gas. They’re currently working on the Dugas & LeBlanc property, north of LA-70 and two geo-probe wells have been placed on Triche property. DNR is currently looking for locations as well as willing individual property owners to place additional geo-probe observation wells.
The drilling rig is being dismantled and moved out today and will be replaced with the snubbing rig as we advised earlier this week. No road closures are anticipated; however, travelers may encur intermittent traffic congestion as equipment is being moved.
The drilling performed by the sonic rig, on Dugas & LeBlanc property on the south side of LA-70, has been halted. We have been advised that gas was encountered at 90 feet. We have no additional details at this time. Parish officials and state agencies are currently at the site. We will advise further once information is available.
Update - video they just now released: It has grown and taking over the pipeline area and starting to go to the other side. Compare the new video with the one below, it shows how much more it has grown in 2 days.
What they say about the video on the Assumption site:
On yesterday, Texas Brine reported a 20′ x 20′ growth of the sinkhole. In the video of the sinkhole site, at approximately 00:35 you can see this growth towards and into the pipeline right of way.
Here is 9/15/12 video they released. It is from the ground level looking at the sinkhole.
Remember there are gas bubbles throughout Bayou Corne. The situation there has not abated and it seems to be getting more troubling.
I have posted about all the earthquakes there this last week.
Here is the graph of quakes so far today - 9/18/12
Update - latest information on Assumption Wordpress from this morning 9/18/12:
As stated on yesterday, DNR has ordered all companies with active industry on the salt dome (Texas Brine, Chevron, Cross Tex, Dow, Pro Mix, Acadian, and PB Energy) to investigate for the presence of natural gas and ordered to vent any gas found. Each company was required to submit their plans regarding this order to DNR. Parish officials and state agencies will review and discuss these plans this afternoon at the industry meeting. The parish should also be receiving engineered plans from DNR for the vent wells that will be placed within the community sometime this week.
No comments:
Post a Comment