It looks like you're using an Ad Blocker.
Please white-list or disable AboveTopSecret.com in your ad-blocking tool.
Some features of ATS will be disabled while you continue to use an ad-blocker.
Giving you guys a tid bit of info,as I am currently researching it. The effect of the moon on Earths lithosphere. Besides causing the oceans to wane back and forth,the tides,it also causes the earth's crust to deform,or "bulge". ~ 30 cm, then the tidally induced average radial expansion is ~ 5 cm (ie., the Earth's crust oscillates from -25 to +35 cm). This result seems plausible, and may be Order-of-Magnitude accurate. www.physicsforums.com...
Another interesting theory is glacial rebound. That is the weight of the ice on the crust actually causing it to depress. Now,take in fact that many glaciers have retreated,and iceshelves have become smaller and broken off. People often wonder how thick the glacial ice was that covered North Dakota. When asked, my response has usually been "I don't know," but sometimes I've speculated if the questioner has persisted. My answer is usually something like "The ice may have been as much as a mile thick in the northeastern corner of North Dakota at Pembina, which is where I think it was the thickest in North Dakota," or "It was up to 8,000 feet thick near Hudson Bay." But I've never done any kind of study myself to verify whether my estimate for North Dakota was even close to being correct. This "Geologic Note" will deal with the question of the thickness of the glacial ice and with isostatic depression and rebound of the earth's crust due to the effects of glaciation, especially in eastern North Dakota. There would seem to be a number of ways to get at the answer to the question "how thick was the glacier?" We can make comparisons with existing glaciers in places like Greenland and Antarctica, but these may or may not be typical of the glaciers that covered North Dakota 20,000 years ago, near the maximum of the most recent glaciation, the Late Wisconsinan glaciation. Another way of indirectly getting at the answer of how much ice existed during the Ice Age is to determine the amount that sea level dropped at the time - the amount of the drop must represent the water that was tied up as glacial ice during the Ice Age. www.dmr.nd.gov...
Anyone living along the coast knows that at certain times,the tides are "running".Meaning the are more extreme then at other times of the year. I learned this during shrimping season in Charleston. But,It also affects the lithosphere,or crust of the Earth.
reply to post by zworld
Two thoughts. Concerning land over old ocean bed, I hope someday to map out where and how long ago this occurred. This pertains to methane hydrate (MH) formation. Areas that were once in what they call a hydrate stability zone, meaning the pressure and temperature were right for turning methane gas into gas trapped in an ice lattice (methane hydrate), moves out of this zone over time as they get buried deeper, and the temps get to hot for ice, dissociating the hydrates. I call these relic hydrates, pockets of methane gas under intense pressure. I believe most kicks from encountering gas (like Deepwater Horizon) during the drilling process are actually hitting relic hydrates, even on land, as deep under the surface there are areas of ocean bed from millions of years ago that once were in the hydrate stability zone. The reason I bring that up is because MH is affected by EQs in a big way. Massive ocean landslides and other deformations occur when big EQs hit thick MH beds. But thats a different angle to EQs and one I might start a new thread on, MH in general. Its going to be one of the biggest concerns we face in the very near future as the corporate world is banking the grid on MH extraction.
Originally posted by tmiddlebrook36
What I’m about to share with you is 100% fact checkable and I encourage, again, everyone to do just that. The inception of research began in 1992 (less than one year after I began my career), after the 7.3 Landers, CA earthquake and subsequent 6.5 Big Bear, CA earthquake that occurred only three hours later. This single, heavily studied, event changed the way geologist research event sequences to this very day, and not because the two earthquakes were initially thought to be two separate events, than eventually connected via cause, but because of the research that surrounded them.
This seismic hazard map was produced by the Global Seismic Hazard Assessment Program (GSHAP).␣ Launched in 1992, GSHAP promoted a regionally coordinated, homogeneous approach to seismic hazard evaluation, intended for national decision makers and engineers responsible for land-use planning and improved building design and construction.
The NSF EarthScope initiative involves four integrated components: USArray, a moving array of broadband seismic instruments; the San Andreas Fault Observatory at Depth (SAFOD), involving deep drilling and instrumentation at depth; the Plate Boundary Observatory (PBO), primarily an array of continuous GPS stations and strainmeters to be deployed in the western U.S.; and a dedicated InSAR mission for obtaining synoptic information about crustal deformation globally. The first three components of EarthScope are expected to be led by NSF, but NASA can contribute to PBO through its accumulated expertise in space-based geodesy and GPS. NASA should be the lead for a dedicated InSAR mission.
Earthquakes are among nature’s most complex phenomena, threatening many of the world’s population centers. A great Pacific Rim earthquake near a major economic area might cause damages well in excess of one trillion dollars and tens of thousands of casualties. Reaching an understanding of earthquake fault systems is required in order to address the issue of their predictability, with the goal of mitigating their impact
Key questions include:
• How do individual faults behave and interact as part of an integrated system?
• What are the mechanical properties of the crust and mantle that control deformation?
• To what extent can earthquakes be forecast
The ensemble of data combined with advanced geophysical modeling will allow quantitative prediction of many aspects of fault zone deformation.
We have a relatively poor understanding of the dynamics of subduction at ocean trenches, or the mechanism for initiation of new subduction zones. While we generally understand the large-scale thermal structure of mid-ocean ridges and oceanic plates with ages less than about 50 million years, there are still questions about structure at small spatial scales as well as for older oceanic plates and continental plates.
While oceanic crust is thought to be formed by partial melting of mantle rock at depth beneath an ocean ridge, we don’t understand how continental crust is formed or whether recycling of the lower continental crust into the mantle is an important process.
Over the past 150 years, the main (axial dipole) component of the Earth’s magnetic field has decayed by nearly 10%, a rate ten times faster than if the dynamo were simply switched off. To that extent, the dynamo today is operating more as an anti-dynamo, a destroyer of the dipole part of the field. Intriguingly, this decay rate is characteristic of magnetic reversals, which paleomagnetic observations have shown occur on average, though with great variability, about once every half million years
As molten iron cools down it crystallizes at 1538°C into its δ allotrope, which has a body-centered cubic (bcc) crystal structure. As it cools further its crystal structure changes to face-centered cubic (fcc) at 1394 °C, when it is known as γ-iron, or austenite. At 912°C the crystal structure again becomes bcc as α-iron, or ferrite, is formed, and at 770°C (theCurie point, Tc) iron becomes magnetic
As I’ve mentioned to look for increasingly obvious programing and PSA’s over the next month, I’ve provided a benchmark for my credibility. Tomorrow nigh KLCS is running and entire program, live, entitled “TOTALLY UNPREPARED”. Please watch it as this is what I’m referring to. I’m not sure how to be more vulnerable here to make my point. Obviously, I cannot reveal my true identity and I would ask those of you who are trying to expose me to redirect your attention to spreading the word.
Originally posted by Robin Marks I see nothing unnatural or impeding in California. I'd not be surprised by a Cascadian megaquake. We all know this is a real possibility.
not good. must stop any way we can. When you include the sonar testing they do which adds pressure as well, and all the weight from cities, roads, resevoirs etc etc. not good
I wrote something the other day on the Arkansas thread. I went a bit over the top. The problem is that I meant every word of it. I went nuts when I discovered the fact that Texas has 53 000 injection wells. That's not including the fracking wells.
reply to post by Robin Marks
I don't know how to make it any clearer than this. A disaster in the midwest is coming. And it will be manmade.
Originally posted by zworld
reply to post by MamaJ
Will do MamaJ.
In a couple days when I get some time Im going to post about MH and how an oceanic landslide caused by it following the Japan EQ may have been partly responsible for the height of the tsunami.
Scientists on Thursday unveiled the most detailed portrait yet of a mysterious region of the planet that human eyes have never seen, and likely never will — the bottom of Earth's tectonic plates.
The work revealed that beneath a 46,000-square-mile (120,000-square-kilometer) region of Southern California, the continental plate is riddled with abrupt jumps in thickness, changing by as much as 18 miles (30 km) over a relatively short distance.
"It surprised us," Lekic told OurAmazingPlanet. "You could probably drive in less than an hour from the part that's very thick to the part that’s very thin. That means that the topography is very steep."
That's one reason the work focused on Southern California, which is an area of active continental rifting — the millions of years-long process that tears land masses apart. (In addition, the region is crowded with sensors maintained by the state itself, and was also the host for several years to a federally operated network of traveling seismometers known as the USArray.)
The scientists were specifically interested in an area known as the Salton Trough, a region just north of the Gulf of California — a long, narrow body of water the local rifting created when the Baja Peninsula was severed from the North American mainland millions of years ago.
It was directly beneath this rifting region that the lithosphere got so thin, Lekic said.
The geologic forces that shape the Earth's surface do their work in the lithosphere, often out of sight and far below the surface. Researchers have now measured the lithosphere’s thickness in southern California. It varies widely, from less than 25 miles to nearly 60 miles. Credit: Fischer Lab, Brown University Rifting is one of the fundamental geological forces that have shaped our planet. Were it not for the stretching of continents and the oceans that filled those newly created basins, Earth would be a far different place. Yet because rifting involves areas deep below the Earth's surface, scientists have been unable to understand fully how it occurs.
Friday, October 07, 2011 at 22:10:10 UTC
Friday, October 07, 2011 at 03:10:10 PM at epicenter
0 km (~0 mile) (poorly constrained)
20 km (13 miles) SW (230°) from Scottys Castle, CA
49 km (30 miles) SSW (208°) from Tokop, NV
57 km (35 miles) SSE (161°) from Sylvania, NV
62 km (38 miles) NE (53°) from Lone Pine, CA
84 km (52 miles) NNE (31°) from Olancha, CA
220 km (137 miles) WNW (292°) from Las Vegas, NV
horizontal +/- 1.8 km (1.1 miles); depth +/- 4.5 km (2.8 miles)
Nph= 17, Dmin=16 km, Rmss=0.48 sec, Gp=130°,
M-type=local magnitude (ML), Version=1
California Integrated Seismic Net:
USGS Caltech CGS UCB UCSD UNR