TY  - JOUR
A1  - Steinberg, Andreas
A1  - Vasyura-Bathke, Hannes
A1  - Gaebler, Peter Jost
A1  - Ohrnberger, Matthias
A1  - Ceranna, Lars
T1  - Estimation of seismic moment tensors using variational inference machine learning
JF  - Journal of geophysical research : Solid earth
N2  - We present an approach for rapidly estimating full moment tensors of earthquakes and their parameter uncertainties based on short time windows of recorded seismic waveform data by considering deep learning of Bayesian Neural Networks (BNNs). The individual neural networks are trained on synthetic seismic waveform data and corresponding known earthquake moment-tensor parameters. A monitoring volume has been predefined to form a three-dimensional grid of locations and to train a BNN for each grid point. Variational inference on several of these networks allows us to consider several sources of error and how they affect the estimated full moment-tensor parameters and their uncertainties. In particular, we demonstrate how estimated parameter distributions are affected by uncertainties in the earthquake centroid location in space and time as well as in the assumed Earth structure model. We apply our approach as a proof of concept on seismic waveform recordings of aftershocks of the Ridgecrest 2019 earthquake with moment magnitudes ranging from Mw 2.7 to Mw 5.5. Overall, good agreement has been achieved between inferred parameter ensembles and independently estimated parameters using classical methods. Our developed approach is fast and robust, and therefore, suitable for down-stream analyses that need rapid estimates of the source mechanism for a large number of earthquakes.
KW  - seismology
KW  - machine learning
KW  - earthquake source
KW  - moment tensor
KW  - full
KW  - waveform
Y1  - 2021
U6  - https://doi.org/10.1029/2021JB022685
SN  - 2169-9313
SN  - 2169-9356
VL  - 126
IS  - 10
PB  - American Geophysical Union
CY  - Washington
ER  - 
TY  - JOUR
A1  - Izgi, Gizem
A1  - Eken, Tuna
A1  - Gaebler, Peter
A1  - Eulenfeld, Tom
A1  - Taymaz, Tuncay
T1  - Crustal seismic attenuation parameters in the western region of the North Anatolian Fault Zone
JF  - Journal of geodynamics
N2  - Detailed knowledge of the crustal structure along the North Anatolian Fault Zone can help in understanding past and present tectonic processes in relation to the deformation history. To estimate the frequency-dependent crustal attenuation parameters beneath the western part of the North Anatolian Fault Zone we apply acoustic radiative transfer theory under the assumption of multiple isotropic scattering to generate synthetic seismogram envelopes. The inversion depends on finding an optimal fit between observed and synthetically computed coda wave envelopes in five frequency bands. 2-D lateral variation of intrinsic and scattering attenuation at various frequencies tends to three crustal blocks (i.e., Armutlu-Almacik, Istanbul-Zonguldak and Sakarya Zones) separated by the southern and northern branches of the western part of the North Anatolian Fault Zone. Overall, scattering attenuation appears to be dominant over intrinsic attenuation in the study area at lower frequencies. Relatively low attenuation properties are observed beneath the older Istanbul Zone whereas higher attenuation properties are found for the younger Sakarya Zone. The Armutlu Almacik Zone exhibits more complex lateral variations. Very high attenuation values towards the west characterize the area of the Kuzuluk Basin, a pull-apart basin formed under west-east extension. Our coda-derived moment magnitudes are similar to the local magnitude estimates that were previously calculated for the same earthquakes. For smaller earthquakes (M-L < 2.5), however, the relation between local and moment magnitudes appears to lose its coherency. This may stem from various reasons including the use of seismic data recorded in finite sampling interval, possible biases in local magnitude estimates of earthquake catalogues as well as biases due to wrong assumptions to consider anelastic attenuation terms.
Y1  - 2020
U6  - https://doi.org/10.1016/j.jog.2020.101694
SN  - 0264-3707
VL  - 134
PB  - Elsevier
CY  - Oxford
ER  - 
TY  - JOUR
A1  - Koenig, Julian
A1  - Abler, Birgit
A1  - Agartz, Ingrid
A1  - akerstedt, Torbjorn
A1  - Andreassen, Ole A.
A1  - Anthony, Mia
A1  - Baer, Karl-Juergen
A1  - Bertsch, Katja
A1  - Brown, Rebecca C.
A1  - Brunner, Romuald
A1  - Carnevali, Luca
A1  - Critchley, Hugo D.
A1  - Cullen, Kathryn R.
A1  - de Geus, Eco J. C.
A1  - de la Cruz, Feliberto
A1  - Dziobek, Isabel
A1  - Ferger, Marc D.
A1  - Fischer, Hakan
A1  - Flor, Herta
A1  - Gaebler, Michael
A1  - Gianaros, Peter J.
A1  - Giummarra, Melita J.
A1  - Greening, Steven G.
A1  - Guendelman, Simon
A1  - Heathers, James A. J.
A1  - Herpertz, Sabine C.
A1  - Hu, Mandy X.
A1  - Jentschke, Sebastian
A1  - Kaess, Michael
A1  - Kaufmann, Tobias
A1  - Klimes-Dougan, Bonnie
A1  - Koelsch, Stefan
A1  - Krauch, Marlene
A1  - Kumral, Deniz
A1  - Lamers, Femke
A1  - Lee, Tae-Ho
A1  - Lekander, Mats
A1  - Lin, Feng
A1  - Lotze, Martin
A1  - Makovac, Elena
A1  - Mancini, Matteo
A1  - Mancke, Falk
A1  - Mansson, Kristoffer N. T.
A1  - Manuck, Stephen B.
A1  - Mather, Mara
A1  - Meeten, Frances
A1  - Min, Jungwon
A1  - Mueller, Bryon
A1  - Muench, Vera
A1  - Nees, Frauke
A1  - Nga, Lin
A1  - Nilsonne, Gustav
A1  - Ordonez Acuna, Daniela
A1  - Osnes, Berge
A1  - Ottaviani, Cristina
A1  - Penninx, Brenda W. J. H.
A1  - Ponzio, Allison
A1  - Poudel, Govinda R.
A1  - Reinelt, Janis
A1  - Ren, Ping
A1  - Sakaki, Michiko
A1  - Schumann, Andy
A1  - Sorensen, Lin
A1  - Specht, Karsten
A1  - Straub, Joana
A1  - Tamm, Sandra
A1  - Thai, Michelle
A1  - Thayer, Julian F.
A1  - Ubani, Benjamin
A1  - van Der Mee, Denise J.
A1  - van Velzen, Laura S.
A1  - Ventura-Bort, Carlos
A1  - Villringer, Arno
A1  - Watson, David R.
A1  - Wei, Luqing
A1  - Wendt, Julia
A1  - Schreiner, Melinda Westlund
A1  - Westlye, Lars T.
A1  - Weymar, Mathias
A1  - Winkelmann, Tobias
A1  - Wu, Guo-Rong
A1  - Yoo, Hyun Joo
A1  - Quintana, Daniel S.
T1  - Cortical thickness and resting-state cardiac function across the lifespan
BT  - a cross-sectional pooled mega-analysis
JF  - Psychophysiology : journal of the Society for Psychophysiological Research
N2  - Understanding the association between autonomic nervous system [ANS] function and brain morphology across the lifespan provides important insights into neurovisceral mechanisms underlying health and disease. Resting-state ANS activity, indexed by measures of heart rate [HR] and its variability [HRV] has been associated with brain morphology, particularly cortical thickness [CT]. While findings have been mixed regarding the anatomical distribution and direction of the associations, these inconsistencies may be due to sex and age differences in HR/HRV and CT. Previous studies have been limited by small sample sizes, which impede the assessment of sex differences and aging effects on the association between ANS function and CT. To overcome these limitations, 20 groups worldwide contributed data collected under similar protocols of CT assessment and HR/HRV recording to be pooled in a mega-analysis (N = 1,218 (50.5% female), mean age 36.7 years (range: 12-87)). Findings suggest a decline in HRV as well as CT with increasing age. CT, particularly in the orbitofrontal cortex, explained additional variance in HRV, beyond the effects of aging. This pattern of results may suggest that the decline in HRV with increasing age is related to a decline in orbitofrontal CT. These effects were independent of sex and specific to HRV; with no significant association between CT and HR. Greater CT across the adult lifespan may be vital for the maintenance of healthy cardiac regulation via the ANS-or greater cardiac vagal activity as indirectly reflected in HRV may slow brain atrophy. Findings reveal an important association between CT and cardiac parasympathetic activity with implications for healthy aging and longevity that should be studied further in longitudinal research.
KW  - aging
KW  - autonomic nervous system
KW  - cortical thickness
KW  - heart rate
KW  - heart
KW  - rate variability
KW  - sex
Y1  - 2020
U6  - https://doi.org/10.1111/psyp.13688
SN  - 0048-5772
SN  - 1469-8986
VL  - 58
IS  - 7
PB  - Wiley
CY  - Hoboken
ER  -