scholarly journals Crustal thickness and Moho sharpness beneath the Midcontinent rift from receiver functions

2013 ◽  
Vol 3 (1) ◽  
pp. 1 ◽  
Author(s):  
Moikwathai Moidaki ◽  
Stephen S. Gao ◽  
Kelly H. Liu ◽  
Estella Atekwana
Keyword(s):  
South Dakota ◽  
Volcanic Eruptions ◽  
Crustal Thickness ◽  
Receiver Functions ◽  
Earth Model ◽  
Basaltic Lava ◽  
Continental Lithosphere ◽  
Mean Velocity ◽  
Midcontinent Rift ◽  
Rift Valleys

The Mesoproterozoic Midcontinent rift (MCR) in the central US is an approximately 2000 km long, 100 km wide structure from Kansas to Michigan. During the 20-40 million years of rifting, a thick (up to 20 km) layer of basaltic lava was deposited in the rift valleys. Quantifying the effects of the rifting and associated volcanic eruptions on the structure and composition of the crust and mantle beneath the MCR is important for the understanding of the evolution of continental lithosphere. In this study we measure the crustal thickness (H), and the sharpness of the Moho (R) at about 24 portable and permanent stations in Iowa, Kansas, and South Dakota by stacking Pto- S converted waves (PmS) and their multiples (PPmS and PSmS). Under the assumption that the crustal mean velocity in the study area is the same as the IASP91 earth model, we find a significantly thickened crust beneath the MCR of about 53 km. The crustal V<sub>p</sub>/V<sub>s</sub> ratios increases from about 1.80 off rift to as large as 1.95 within the rift, which corresponds to an increase of Poisson’s ratio from 0.28 to 0.32, suggesting a more mafic crust beneath the MCR. The R measurements are spatially variable and are relatively small in the vicinity of the MCR, indicating the disturbance of the original sharp Moho by the rifting and magmatic intrusion and volcanic eruption.

Simultaneous inversion for crustal thickness and anisotropy by multiphase splitting analysis of receiver functions

2020 ◽  
Vol 223 (3) ◽  
pp. 2009-2026
Author(s):  
Frederik Link ◽  
Georg Rümpker ◽  
Ayoub Kaviani
Keyword(s):  
Statistical Tests ◽  
Real Data ◽  
Crustal Thickness ◽  
Receiver Functions ◽  
S Wave ◽  
Arrival Times ◽  
Simultaneous Inversion ◽  
Correction Scheme ◽  
Converted Phases ◽  
Two Phases

SUMMARY We present a technique to derive robust estimates for the crustal thickness and elastic properties, including anisotropy, from shear wave splitting of converted phases in receiver functions. We combine stacking procedures with a correction scheme for the splitting effect of the crustal converted Ps-phase and its first reverberation, the PpPs-phase, where we also allow for a predefined dipping Moho. The incorporation of two phases stabilizes the analysis procedure and allows to simultaneously solve for the crustal thickness, the ratio of average P- to S-wave velocities, the percentage of anisotropy and the fast-axis direction. The stacking is based on arrival times and polarizations computed using a ray-based algorithm. Synthetic tests show the robustness of the technique and its applicability to tectonic settings where dip of the Moho is significant. These tests also demonstrate that the effects of a dipping layer boundary may overprint a possible anisotropic signature. To constrain the uncertainty of our results we perform statistical tests based on a bootstrapping approach. We distinguish between different model classes by comparing the coherency of the stacked amplitudes after moveout correction. We apply the new technique to real-data examples from different tectonic regimes and show that coherency of the stacked receiver functions can be improved, when anisotropy and a dipping Moho are included in the analysis. The examples underline the advantages of statistical analyses when dealing with stacking procedures and potentially ambiguous solutions.

Determination of crustal thickness and velocities by using receiver functions andPmPtravel times

2018 ◽  
Vol 216 (2) ◽  
pp. 1304-1312 ◽  
Author(s):  
Song Luo ◽  
Lupei Zhu ◽  
Rong Huang ◽  
Yinhe Luo ◽  
Xiaohuan Jiang ◽  
...  
Keyword(s):  
Crustal Thickness ◽  
Receiver Functions

Crustal thickness beneath Central and East Java (Indonesia) inferred from P receiver functions

2016 ◽  
Vol 115 ◽  
pp. 69-79 ◽  
Author(s):  
Ingo Wölbern ◽  
Georg Rümpker
Keyword(s):  
Crustal Thickness ◽  
Receiver Functions

Crustal Thickness Estimatives and Vp/Vs Ratio Using Receiver Functions

2011 ◽  
Author(s):  
Diogo Farrapo Albuquerque ◽  
César Garcia Pavão ◽  
Rafael Toscani Gomes da Silveira ◽  
Iago Guilherme dos Santos ◽  
George Sand França
Keyword(s):  
Crustal Thickness ◽  
Receiver Functions

Crustal thickness map of the Chinese mainland from teleseismic receiver functions

2014 ◽  
Vol 611 ◽  
pp. 51-60 ◽  
Author(s):  
Yonghua Li ◽  
Mengtan Gao ◽  
Qingju Wu
Keyword(s):  
Crustal Thickness ◽  
Receiver Functions ◽  
Chinese Mainland ◽  
The Chinese Mainland

Models of crustal thickness for South America from seismic refraction, receiver functions and surface wave tomography

2013 ◽  
Vol 609 ◽  
pp. 82-96 ◽  
Author(s):  
Marcelo Assumpção ◽  
Mei Feng ◽  
Andrés Tassara ◽  
Jordi Julià
Keyword(s):  
Surface Wave ◽  
South America ◽  
Seismic Refraction ◽  
Crustal Thickness ◽  
Receiver Functions ◽  
Surface Wave Tomography ◽  
Wave Tomography

scholarly journals Stacked P ‐to‐ S and S ‐to‐ P receiver functions determination of crustal thickness, V p , and V s : The H‐V stacking method

2016 ◽  
Vol 43 (4) ◽  
pp. 1487-1494 ◽  
Author(s):  
Catherine A. Rychert ◽  
Nicholas Harmon
Keyword(s):  
Crustal Thickness ◽  
Receiver Functions

scholarly journals First seismic constraints on the Martian crust – receiver functions for InSight

2020 ◽  
Author(s):  
Brigitte Knapmeyer-Endrun ◽  
Felix Bissig ◽  
Nicolas Compaire ◽  
Raphael Garcia ◽  
Rakshit Joshi ◽  
...  
Keyword(s):  
Thermal Evolution ◽  
Broad Band ◽  
Landing Site ◽  
Crustal Thickness ◽  
Receiver Functions ◽  
Apparent Velocity ◽  
S Waves ◽  
Complementary Method ◽  
3D Effects ◽  
Insight Mission

&lt;p&gt;NASA&amp;#8217;s InSight mission arrived on Mars in November 2018 and deployed the first very broad-band seismometer, SEIS, on the planet&amp;#8217;s surface. SEIS has been collecting data continuously since early February 2019, by now recording more than 400 events of different types. InSight aims at enhancing our understanding of the internal structure and dynamics of Mars, including better constraints on its crustal thickness. Various models based on topography and gravity observed from the orbit currently vary in average crustal thickness from 30 km to more than 100 km, with important implications for Mars&amp;#8217; thermal evolution, and the partitioning of silicates and heat-producing elements between different layers of Mars.&lt;/p&gt;&lt;p&gt;We present P-to-S and S-to-P receiver functions, which are available for 4 and 3 marsquakes, respectively, up to now. Out of all of the marsquakes recorded to date, these are the only ones with clear enough P- or S-arrivals not dominated by scattering to make them suitable for the analysis. All of the quakes are located at comparatively small epicentral distances, between 25&amp;#176; and 40&amp;#176;. We observe three consistent phases within the first 10 seconds of the P-to-S receiver functions. The S-to-P receiver functions also show a consistent first phase. Later arrivals are harder to pinpoint, which could be due to the comparatively shallow incidence of the S-waves at the considered distances, which prevents the generation of converted waves. Identification of later multiple phases in the P-to-S receiver functions likewise remains inconclusive. To obtain better constraints on velocity, we also calculated apparent velocity curves from the P-to-S receiver functions, but these provide meaningful results for only one event so far, implying a large uncertainty. Due to difficulties in clearly identifying multiples, the receiver functions can currently be explained by either two crustal layers and a thin (25-30 km) crust or three crustal layers and a thicker (40-45 km) crust at the landing site. This model range already improves the present constraints by providing a new maximum value of less than 70 km for the average crustal thickness. Information from noise autocorrelations as a complementary method, identification of P-reverberations and S-precursors in the event recordings, and more extensive modeling, ultimately including 3D-effects, are considered to further our understanding of the waveforms and tighten the constraints on the crust.&lt;/p&gt;

Sign in / Sign up

Export Citation Format

Share Document