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Crustal Deformation - Science topic

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As we all know, PYLITH can simulated crustal deformations with kinds of materials. 2-D and 3-D problems of pure elastic ,plastic and rheological materials.
However,all the above materials are isotropic.
Is there anyone who knows the anisotropic material definition in PYLITH ?
Thanks a lot for your suggestion!
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If the code is for isotropic case, it is unable to be used for anisotropic case.
If the anisotropic case you mentioned is transversely isotropic, I think I can help because we have code on deformation due to different sources, such as tide generating force, surface mass or stress loading force and dislocation, for this special case. specifically, the case can be degenerated to the isotropic case.
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I am looking for tools for generating realistic folding from layers with varying rheologies (clastic sediments). The specific situation is a thin-skinned fold-thrust belt with prehnite–actinolite facies conditions. Scale/resolution requirement is 1-5m.
Also interesting would be your views what type of approach is more suited, ie. kinematic or process/physical modelling.
Thanks!
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MOVE by petroleum experts Ltd. They give free academic license.
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We perform differential SAR Interferometry for analyzing the land movement. In case of Landslides the area generally suffers from decorrelation. So for the confidence in the result what minimum threshold should be taken so that outliers should be removed?
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Well, it's comprehensively depends on the nature of surface.
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There are many geophysical and remote sensing methods to determine the crustal deformation and active tectonic movements. I need some research papers related to active tectonic movements in eastern part of India.
Thanks.
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Dear Himanshu Chaube,
Indian Institute of Technology Kharagpur.
You could consult the following paper, a very good synthesis:
Ravi Bastia, (2006), "An overview of Indian sedimentary basins with special focus on emerging east coast deepwater frontiers," The Leading Edge 25: 818-829.
This article will provide an overview of the current Indian petroleum exploration scenario with a special focus on the east coast deepwater basins. An attempt has been made to distinguish the hydrocarbon system and play types for both rift-related and other structural styles using high-quality 2D and 3D seismic imaging information. Integrating the geologic information with state-of-the-art seismic data has generated a large portfolio of play types (e.g., channel-levee complex, lobes, syn-rift structural closures, and wedge-outs against basement highs) worthy of exploration.
Cheers, Mario E. Sigismondi
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These ostracods are from north Iran(rice fields and lakes) and their SEM are ready.
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Iam working on recent Ostracods from The Red Sea and River Nile I will be happy to work with you
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Hello,
In a strike slip fault in central Mexico, we record P, R', Y-shear. But R shears are absent. Can someone please suggest similar cases and reasons for such absence.
Thanks
Amar
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Hello Amar,
The experimental works of Mandl, Logan, and their respective co-workers (among other groups) have shown that as shear strain increases in a shear zone, R shears progressively become more and more parallel to the shear zone boundary, ultimately becoming parallel to the Y shears, which eventually take up most of the displacement, together with P shears.
The reason for this may be a progressive rotation from a progessive rotation of the principal stresses within the shear zone as the differential stress increases. Another important factor may be the rigidity of the fault blocks, which restrict the amount of displacement that can be accommodated through R-shear extension.
That may be the reason you don't find any R shears, specially if strain is localised within a narrow zone, which would increase the shear strain for a given displacement.
If you'll allow me, I'd reccommend you specially the following reference, where the development of these structures is widely discussed. I am sorry I can't provide any natural examples.
Logan, J. M., Dengo, C. A., Higgs, N. G., & Wang, Z. Z. (1992). Fabrics of experimental fault zones: their development and relationships to mechanical behavior. Fault Mechanics and Transport Properties of Rocks. https://doi.org/http://dx.doi.org/10.1016/S0074-6142(08)62814-4
Good luck with your research!
Kind regards,
Manuel
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Hello,
My name is An Xiangyi,a student of Korea University,studing structure geology.Now I am studing crustal deformation derived by GPS observations .I have a question that how could I get long term velocity or displacement data from GEONET RINEX data from which the longest period I can get once is 10 days.So it is difficult to collect every 10days for 5 years data.
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Clarifying Brian's assertion, you can use the FTP with a recursive download application, like WGet to grab whatever data you want in an automated manner (no need to use their website form method). 
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Sentinel - 1 product types are:
SH (single HH polarisation)
SV (single VV polarisation)
DH (dual HH+HV polarisation)
DV (dual VV+VH polarisation)
Which polarisation is useful for surface deformation studies?
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If you are interested in ground deformation, use HH images in StripSAR (they could be FBD or FBS, does not matter). 
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Receiver function and crustal structure modeling
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Dear RG members
I want to have a clarification so that I may be able to understand it.
With best regards
IJAZ
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Elaborating upon David's description which I fully agree with; This combined (complexely amalgamated words....) term refers to a terminology of the late seventies which tried to capture/describe the mosaic of fragments of tectonic plates which is visible along the edges of the main and minor Plates; being made up of elements that belonged to both bounding plates and to plates that had long disappeared, it became in-vogue to speak of "terranes". The terminology is based on the concept that each of these "terranes" shows it's own unique (tectono-)stratigraphy. Later on it was recognized that this may be an oversimplification of reality and a too-rigid way of trying to define the geological reality.
How big these "terranes" are is not really clear, so the concept can be applied on various scales (hm, km). It can still be useful for descriptive purposes, especially when we look at plate boundaries characterized by a large horizontal component where different structural blocks are now facing each other in a completely unique way with respect to their origins. But then we could simply use the word "block". When we look at overthrusting it is obvious that different structural units by definition show a unique stratigraphy so the terminology is not really useful in that case according to many authors. So here we talk about "thrust sheets" or "nappes".
Obviously what is "complex" depends of our view of the world. That can be very personal and subjective if "complex" becomes synonymous of "most people do not understand it". Which can then be followed by "but I do, instead", or by "neither do I". ;-)
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I have some GPS data  high frequency 1hz of the last earthquake in Algiers Ml=5.4 and I would like to know with which software I can process my data ?
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For your high precision application (small crustal movements), you must use GPS research software as Bernese (Bern University), Gamit (Massachusetts  Institute of Technology)  or Gipsy (Jet propulsion Laboratory / NASA).
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as mentioned in Fialko 2001 for 3 D displacement from InSAR, a linear system of equations should be solved for each pixel :
1.Two equations from Ascending and Descending Orbits
  [Un Sin φ – Ue Cos φ] Sin θ + Uu Cos θ + δlos = dr ……….. (1)
Where,
  φ … The azimuth of the satellite heading vector (positive
           clockwise from the North)
  θ … The radar incidence angle at the reflection point
  dr … The LOS displacement at the reflection point
  δlos … Is the relative measurement error
2.
One equation for the Azimuthal Offset from the descending orbit
  Un Cos φ + Ue Sin φ + δazo = dazo ………………….……….. (2)
my question is how to obtain dazo from an unwrapped differential interferogram.
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Have a look into the paper of Joughin et al. 1998 I have attached. Though it explains how to tetermine the 3D flow vector of an ice-flow by using ERS-interferometry, the principle should be the same as in your case.
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Apart from applying the technique in fold thrust belts which are deformed in a thin skinned manner, can we also use this in any other tectonic regime?
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The short answer is yes, why not. Any cross-section balancinfg techniques (I guess you mean line- and area-balancing) will work on most sections, regardless of the type of tectonics (extensional or contractional, for instance). However, the reason you see mostly balancing of thin-skinned tectonics in publications is that they are far easier to balance! More specifically, thin-skinned tectonics allow far more surface data to be included in the model, especially for construction of the beds and determination of the detachment level, whereas thick-skinned requires data from deep in the subsurface, which is only available from seismics and boreholes.
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To resolve 3 D Surface displacement from DInSAR it is required to know the incidence angle at each target pixel and the azimuth of the satellite heading vector clock wise positive from north to form three equations in three unknowns(Un, Ue, and Uv) for each pixel.
The azimuth vector differs according to the looking direction of the satellite and I use ERS satellites and ENVISAT 
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Mathijs answer is very good, except ERS/Envisat goes west(!) at high latitudes.  At equator, the ascending groundtrack azimuth is: 450deg -98.54deg (orbit inclination)  -3.93deg (earth rotation) =  347.53deg.  Descending at equator is: 90deg +98.54deg +3.93deg =192.47deg.  Azimuth at other latitudes may be found by spherical trigonometry, being 270deg.(west) at high latitudes.
Kjell
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DInSAR produces the surface displacement in only the direction of radar line of sight (LOS) then, how to resolve this vector in the three dimensions East-West, North-South, and Up-down (vertical) for merging with other space geodetic techniques as GPS
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Hi,
you can find a paper on the combination of InSAR with levelling and GPS measurements here: http://gji.oxfordjournals.org/content/203/1/614.abstract
The slides of a presentation on the combination approach held on ESA's Fringe Workshop 2015 in Frascati, Italy, can be found in this pdf-file: http://seom.esa.int/fringe2015/files/presentation80.pdf
The full matrix including the projection of InSAR LOS displacements (ascending as well as descending) is on slide 11.
Cheers, Thomas
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There are two ways for interferometry 
a. apply an external DEM like SRTM
b. Apply a third SAR image to an interferometric pair 
if an External DEM is applied with low accuracy about ten meters or more how is sub-centimeter accuracy achieved ???
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Hi Reda, 
it achieves it in a relative manner. DInSAR is not an absolute measurement principle. So what you actually measure is the relative change in distance from time 1 to time 2. You assuming your DEM therefore as "correct", or  in a more technical way, you use it to substract the topographical component of your interferometric phase. In addition, 2-pass DInSAR does not achieve necessarily sub-centimeter accuracy. Atmospheric conditions might have strong effects (e.g. 14cm for 20% change in relative humidity). If you want to achieve sub-centimetres accuracy, go for multi-temporal approaches like SBAS and/or PS. Those techniques provide you also an DEM error estimation as an additional output. There are some freely available open-source software packages out for research purposes. StaMPS or GiANT for example.
Good luck,
Andreas
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A differential interferogram (DInSAR) can be composed if the phase of one interferogram is subtracted from the phase of another interferogram "DEM" so that the remaining contributions in the phase are those related only to surface displacement.
but how it can be extracted or converted from phase units to metric units displacements per unit time (e.g. cm / year) ?
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The radar is sensitive to surface displacements in the radar line-of-sight. Conversion of phase to cm is based on the wavelength. One fringe corresponds to half the wavelength, i.e. 2*pi radians = - lambda/2. For ERS lambda is about 5.6 cm. In terms of the sign convention a range increase (read positive phase values), mean the radar signal has travelled longer. In other words if reflects a subsidence motion. Therefore a minus sign is often included when converting the phase to a displacement. 
If you are looking to an interferogram then the units are in rad. You can convert that to a velocity by dividing by the temporal baseline of the interferogram. 
Conversion to a North, East and Up component is not trivial. To decompose the LOS for NEU components you will need to make some assumptions. For that I refer you to the literature as suggested by Laszlo. 
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i mean for instance, if it can say that ductile shear zone is dextral inverse or inverse dextral.  
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Yes Sergio, many major shear zones have sections with a normal or thrust component, and are ductile at depth. As soon as the orientation of the shear zone is not perfectly the same as the motion of the blocks it separates, you have oblique motion along the fault. It may even change with time. An example is the Ailao Shan-Red River fault zone in Asia, as described in Leloup et al. (2001), New constraints on the structure, thermochronology, and timing of the Ailao Shan-Red River shear zone, SE Asia, J. Geophys. Res., 106, 6683 – 6732, doi:10.1029/ 2000JB900322.
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For the same geographical position I obtained Three elevations from three different sources of DEMs
For InSAR DEM:
Lat ; 24.29248762   Long  32.2634383    Elev: 92.193  M
For ASTER :
Long; 32.2634383      Lat; 24.29248762      Elev :427.161  M
For SRTM :
Long ; 32.2634382962    ,    Lat ; 24.2924876245,    Elev : 437.485  M
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Dear Reda,
U have to first process the data and check of any sinks or garbage values or no data pixels. then re-sample your data and then check the elevation of same point  on all the DEMS . you error will be reduced
also their is the difference in the elevation if you compare different DEMS a particular DEM can give you best results at some place but there can be large errors at some other places it depends upon the surface roughness in case of SAR data and also the view angle and other sensor properties.
try to validate the results with GPS i.e filed data and check which DEM is showing close relation to your field data. 
Best of Luck 
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At what pressure at surface conditions will frozen Alberta oil sands fail in a lab test, that is, fracture break or shear? Is it very different from frozen mud?
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Thank you for your response, by way of introduction, I am an oil sands geologist with projects associated with the mining and thermal recoveries here in Alberta. My question is at what pressure point does unaltered but frozen bitumen sand fracture fail. This is not a mine plant processing treatment issue but that of mechanical strength. I am looking for quantitative lab data in the literature, if any exits, that I can extrapolate into geomorphological processes during the Pleistocene.
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In geodetic applications, how can one use differential interferometry for crustal displacement monitoring?
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interferograms 
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Estimating 3D deformation can be done by combining Ascending, Descending and MAI Interferograms
My question can we estimate it using only Single Viewing direction InSAR? either Ascending or descending, without using other information like GPS or assuming deformation model? 
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The 2 previous replies are obviously correct that assumptions are required with single line of sight InSAR. However, some attempt has been made by Aftabi et al. 2010 when estimating flow in salt glaciers using InSAR.
Thanks
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It is well known that mafic magmas can pond at the base of the crust and subsequently feed upper crustal reservoirs. Eventually these mafic, stagnated magmas crystallize. But can them keep liquid (or only partially crystallized) during  several millons of years (i.e. 10-20-30 My), after the volcanic front retreated trenchwards, and go on feeding high level magma chambers?
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Not the same, but nice quantifications have been done for the magmatic lens at the top of the plutonic crust beneath oceanic spreading centers. How long can they survive (how fast do they crystalize) without being replenished ? Not much more than a few decades, 100 years at the most. See references below. Considering that the mafic lenses you are interested in are thicker, deeper, and probably (?) less affected by cooling by a hydrothermal system (important factor, difficult to evaluate), I would guess they could survive longer, but not over time scales of 10-20 Myrs. So if the volcanoes above are active over such long periods, that is probably because the lenses at depth are still feeded from time to time, eventhough they retreated trenchward.
Ref:Models of hydrothermal heat output from a convecting, crystallizing,
replenished magma chamber beneath an oceanic spreading center
Lei Liu1 and Robert P. Lowel JOURNAL OF GEOPHYSICAL RESEARCH, VOL. 114, B02102, doi:10.1029/2008JB005846, 2009:"...the simulation results for crystal-suspended models show that heat output and the hydrothermal temperature decrease rapidly and that crystallinity reaches 60% in less than 10 a. In crystal-settling models, magma convection may last for decades, but decreasing heat output and hydrothermal temperatures still occur on decadal timescales...The rate of magma replenishment needed ranges between 5 105 and 5 106 m3 a1,which is somewhat faster than that required for seafloor spreading but less than that
of fluxes to some terrestrial volcanoes on similar timescales".
That same paper has some considerations on how fast an ore deposit can form, which is a sideway to look at the life expectency of the heat source, which could be of interest to you
see also: Mid-Ocean Ridges: Hydrothermal Interactions Between the
Lithosphere and Oceans Geophysical Monograph Series 148
Best wishes
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While acquiring seismic data for fault depth behavior analysis, one has to plot a variety of contour maps like velocity or depth contour maps for geodetic surveys, frequency contour maps for the data acquired, etc. One of the easiest and efficient ways of making contour maps is by using Surfer software.
I want to know how the data can be implemented and interpreted and if someone is ready to collaborate, I am enthusiastic to do so.
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I can use both Surfer and Grapher and using full versions.
Near Surface Models are routinely prepared while doing onland data acquisition for determining the Optimum Depth (OD) of shot holes. I can also create Contour Maps using Surfer, I need to know if I can use sample shots for analysis.