Questions related to Active Tectonics
Paleomagnetic studies show that the South China block was moving northward continuously from 300 to 260 Ma and has experienced an overall ∼27° clockwise rotation since then (Huang et al., 2018) ,and assuming a stationary Emeishan mantle plume, so if I want to do a numerical simulation of the geodynamics of the Emeishan mantle plume based on the above conditions. How can I do it?
Hello Professors and colleagues
I am trying to draw a detailed Tectonic schematic cross section for a subducting slab focusing mainly on the transformation of shales and carbonates into greenschist facies schist and Thermal skarn overlying this slab .. ... i know that less is known about the 3D imagination of subduction zones and specially what happens to the sediments !
But what is the best schematic model i can follow from your opinion ?
Suggest references or attach your own images would enrich our discussion :)
Thanks in advance
I need to apply LiDAR for fault growth analysis project to study the presence of Strike-slip faults in strain linkage extensional regime.
Do you know the best commercial software for analysis of high resolution seismic profiles and low price software, but good quality?
It is well known that SAR (Synthetic Aperture Radar) interferometry is based on the SAR technology. How SAR can detect the deformation in three dimensions after earthquake happen? is it possible to measure the slip rate and fault parameters from SAR technology?
Landslides , in general, are found to follow a scaling relationship (V= n*As) between area (A) and volume (V) in which scaling exponent (s) plays significant role.
However, there are two schools of thought regarding this scaling exponent;
1) S is not controlled by landslide material and relation is regulated by geometry.
2) S is controlled by material type.
The question is designed to triger a scientific disscussion about this important issue, correct some misconceptions concerning the whole spectrum of the area's seismicity. ( Instrumental, historical, paleo and archaeo seismicity.
The fitting plane is f(x,y)=ax+by+c
STRIKE = arctg (-b/a)
DIP = arctg (sqrt(a^2 + b^2)).
Thanks for your help.
Some think that 25 December 2016 magnitude 7.7 earthquake might be aftershock of the 1960 M9.5 earthquake. My question is how M7.7 earthquake could be considered aftershock? Isn't it too big for aftershock? To me, there should be upper limit of the magnitude of the aftershock! Anyone help me to understand this phenomenon.
I need some information to study active tectonic in shore lines and coastal area. please help me and send me some papers are useful in this path.
From Unwrapped SAR Interferogram Line of Sight (LOS) component & from the sub-pixel correlation of optical imagery, NS and EW true horizontal components are derived. Is it possible to get the true vertical component from these three derived components?
In case of non availability of the core drill can one use rock splitter that form square shape for the same measurement?
1. I once attributed "angular with irregular shape" of zircon to "relatively short-distance transportation and weak rounding". However, now I think the crushing procedure is very likely to produce irregular zircons by breaking them into pieces. So how can I eliminate one of the two possibilities or indentify which possibility playes the main role?
2. What does Index of Compositional Variability (ICV; Cox et al. 1995) really reflect? I know that high ICV values possibly imply a chemically immature source in active tectonic settings while low ICVs are opposite. However, does ICV have a relationship with the distance of transportation of the sedimentary materials. I mean, can high ICV values reflect short distance of transportation? Does ICV only reflect the information of the source area not that of the transportation process ? If not, can you suggest one or two index to measure the distance of transportation of the sedimentary materials, or give me some advice on how to prove that the sedimantary materials of one area have experienced a short not long distance of transportation.Thank you!
I want to know what 's steep subduction more , The Nazca plate beneath the South American plate or Pacific plate beneath the North America plate?
Highly matured Permian sediments (0.6%vro) occurr at shallow depth(~300m). Why is that? How is the tectonic history related to thermal history in these basins? What are the geological ages of different tectonic phases?
In the last 150 Ma, India seems to have traveled a great distance from the near south pole location to the northern hemisphere. Stratigraphic evidences coupled with ocean bottom studies and other proofs have helped us to reconstruct the evolutionary process behind the inter-plate dynamics. However, the variability observed for continental drifts in terms of directions and speed are too diverse. Can anyone suggest good review papers to understand the present stage of understanding on this issue?
For the NGA West GMPE's Matlab codes are offered by J. Baker. Is anyone aware of a site that offers the GMPE's for Subduction Zone interfaces and the Stable continental regions as used in the Nat. Seismic hazard maps 2014?
Alkaline magmatism often accommpains rifting of continental crust (e.g. Afar province). Regional seismic lines along (magma rich) continental margins often display packages of lava flows interlayered within the syn-rift megasequence continental facies. These packages are sometimes refered to as seawards dipping reflectors or SDRS (e.g., Orange Basin of Namibia).
Whether a continental margin developed is magma poor or magma rich, most rift settings are accommpained by a certain amount of magmatism, which I understand is the result of partial melting generated by decompresion melting. Such decompression results from the crustal stretching related with rifting. My question is, how much of this crustal extension is needed for triggering the magmatic activity observed in rift settings.
3D-1D broadband simulations of ground motion are normally performed by using a hybrid approach where full wave numerical methods are used for the low frequencies and a stochastic contribution has added a posteriori to achieve high frequencies. The cross-over for hybridization is established empirically in a band between about 0.5 Hz and 2 Hz depending on the earthquake magnitude size, distance, local structure and shape of Fourier spectra of low frequency synthetic seismograms.
One of the experts of active fault interprets that there is no clear evidence indicating recent faulting on these seismic profiles, although he cannot perfectly deny the existence of active fault at the locations pointed by arrows. Can you give us your interpretation?
The question concerns seismicity, its spatiotemporal distribution and different models of viewing foreshocks ...
Can someone please help me obtain the effective dates of operation, location and sensitivities for seismic stations used to create the centennial catalog? I am analyzing ~90 regions of the world for completeness of the series (including potential clumping or trends) for events >= M6.5? I have requested this from the USGS, but the request appears to be lost with no answer.
Sedimentation in alluvial fans is considered as geological action that takes place annually with floods, active faults may be registered within some fans
In relationship with the question about hydraulic fracking and earthquake occurrence, I think is worth to imagine that tidal forces (the gravitational pull from both the moon and sun) could have much more energy to trigger an earthquake. Trigging earthquake and not causing it: I mean that already the stress is at a maximum and very close to the breaking. In this situation I think that tidal forces could give the small amount of stress to imitate the earthquake. Did anybody have studied occurrence timing of earthquakes with relationship to maximum tidal effect?
I recently started to look for active faulting in the Kenyan Rift, particularly in the southern part around Lake Nakuru and south of it and I find oddly few publications on neotectonic and/or paleoseismic studies in the region. Can anyone help me with literature or personal experience?
Do the small magnitude earthquakes that we often experience in this part of the world affect river processes such as sinuosity, erosion and deposition? How could we study these controls and effects of microseismic events?
I am trying to determine the acoustic source level at the rock/water interface from shallow earthquakes near the mid-ocean ridge.