Lateral variations in the crustal structure of the Indo-Eurasian collision zone

We thank Michael Ritzwoller and two anonymous reviewers for constructive comments that have helped improve the manuscript. The majority of the seismic data used in this study were downloaded from IRIS DMC. Data for the NGRI stations in India were provided by S. S. Rai, and Zahid Rafi provided the PMD Pakistan data. Kajal Borah provided the ambient noise cross-correlations for the Uttaranchal network. Figures were prepared using Generic Mapping Tools (GMT) software (Wessel and Smith, 1998). We thank Robert Herrmann for making the Computer Programs in Seismology freely available.Peer reviewedPublisher PD

Ohio: Individual State Report - State Level Field Network Study of the Implementation of the Affordable Care Act

This report is part of a series of 21 state and regional studies examining the rollout of the ACA. The national network -- with 36 states and 61 researchers -- is led by the Rockefeller Institute of Government, the public policy research arm of the State University of New York, the Brookings Institution, and the Fels Institute of Government at the University of Pennsylvania.Over the past year, state agency leadership and some members of the legislature have taken an interest in exploring various healthcare reforms in Ohio that address rising healthcare costs and identifying ways to improve healthcare quality, efficiency, and improve overall health outcomes for Ohioans. For example, the legislature included language around healthcare price transparency in the most recent state budget and formed a study committee for the summer of 2015 with the purpose of examining healthcare efficiencies that lead to better health outcomes at a lower cost to Ohioans

Cluster analysis of velocity models around the hudson bay region, Eastern Canada

Acknowledgements All the clustering was performed using tools from Scikit-learn (Pedregosa et al. 2011), a free open source Machine Learning for python programming language. All the maps were created using PyGMT (Uieda et al. 2021). We would like to thank Dr. David Cornwell (University of Aberdeen) for helpful suggestions that resulted in the improvement of this manuscript, and the editor Ian Bastow and two anonymous reviewers for comments that have helped improve the manuscript.Peer reviewedPostprin

The formation of Laurentia : Evidence from shear wave splitting

The authors would like to thank A. Walker for invaluable help understanding the MSAT forward modelling code, as well as A. Boyce, L. Petrescu, and C. Ogden of the ICcratons group for numerous enlightening conversations about Canadian Precam- brian geology and beyond. M.V. Liddell is funded by an Imperial College President’s Scholarship. F.A. Darbyshire is supported by the Natural Sciences and Environment Research Council of Canada through their Discovery Grant and Canada Research Chair programmes.Peer reviewedPublisher PD

Constraints on fracture distribution in the Los Humeros geothermal field from beamforming of ambient seismic noise

Funding Information: The work contained in this paper contains work conducted during a PhD study undertaken as part of the Centre for Doctoral Training (CDT) in Geoscience and the Low Carbon Energy Transition, and it is sponsored by the University of Aberdeen via their NERC GeoNetZero CDT Scheme.Peer reviewedPublisher PD

Seismological constraints on the density, thickness and temperature of the lithospheric mantle in southwestern Tibet

H. M.-D. thanks H. Fang, D. Forsyth, R. G. Green, A. Holt, V. Levin, C. Yu and especially L. Royden for helpful discussions, and to Schlumberger for a scholarship. He is also grateful to V. Levin and S. Roecker for making all seismo-grams from the Y2 network freely available through the IRIS Data Management Centre. We also thank three anonymous reviewers for thorough, constructive reviews. Data were processed using ObsPy. All figures were prepared using Matplotlib, alongside the Cartopy library for mapping.Peer reviewedPostprin

The crustal structure of the western Himalayas and Tibet

We present new, high-resolution, shear velocity models for the western Himalayas and West Tibet from the joint inversion of P receiver functions recorded using seismic stations from four arrays in this region and fundamental mode Rayleigh wave group velocity maps from 5–70 s covering Central and Southern Asia. The Tibetan Plateau is a key locality in understanding large-scale continental dynamics. A large number of investigations has examined the structure and processes in eastern Tibet; however, western Tibet remains relatively understudied. Previous studies in this region indicate that the western part of the Tibetan Plateau is not a simple extension of the eastern part. The areas covered by these arrays include the Karakoram and Altan-Tagh faults, and major terrane boundaries in West Tibet and the Himalayas. The arrays used include broadband data collected by the West Tibet Array, a U.S.-China deployment on the western side of the Tibetan Plateau between 2007 and 2011. We use the shear wave velocity models to obtain estimates of Moho depth. The Moho is deep (68–84 km) throughout West Tibet. We do not observe significant steps within the Moho beneath West Tibet. A large step in Moho depth is observed at the Altyn-Tagh fault, where Moho depths are 20–30 km shallower to the north of the fault compared to those to the south. Beneath the Lhasa Terrane and Tethyan Himalayas, we observe a low-velocity zone in the midcrust. This feature is not interrupted by the Karakoram Fault, suggesting that the Karakoram Fault does not cut through the entire crust

Deciphering the Fate of Plunging Tectonic Plates in Borneo

What happens when subduction stops? A team of scientists installed a dense seismic network in Borneo to investigate causes and consequences of subduction termination

Seismological structure of the 1.8 Ga Trans-Hudson Orogen of North America

Precambrian tectonic processes are debated: what was the nature and scale of orogenic events on the younger, hotter, and more ductile Earth? Northern Hudson Bay records the Paleoproterozoic collision between the Western Churchill and Superior plates—the ∼1.8 Ga Trans-Hudson Orogeny (THO)—and is an ideal locality to study Precambrian tectonic structure. Integrated field, geochronological, and thermobarometric studies suggest that the THO was comparable to the present-day Himalayan-Karakoram-Tibet Orogen (HKTO). However, detailed understanding of the deep crustal architecture of the THO, and how it compares to that of the evolving HKTO, is lacking. The joint inversion of receiver functions and surface wave data provides new Moho depth estimates and shear velocity models for the crust and uppermost mantle of the THO. Most of the Archean crust is relatively thin (∼39 km) and structurally simple, with a sharp Moho; upper-crustal wave speed variations are attributed to postformation events. However, the Quebec-Baffin segment of the THO has a deeper Moho (∼45 km) and a more complex crustal structure. Observations show some similarity to recent models, computed using the same methods, of the HKTO crust. Based on Moho character, present-day crustal thickness, and metamorphic grade, we support the view that southern Baffin Island experienced thickening during the THO of a similar magnitude and width to present-day Tibet. Fast seismic velocities at >10 km below southern Baffin Island may be the result of partial eclogitization of the lower crust during the THO, as is currently thought to be happening in Tibet

Lithospheric deformation in the Canadian Appalachians : evidence from shear wave splitting

This work was funded by Leverhulme Trust research project grant RPG-2013-332. Imperial College Maritimes network stations were provided through Natural Environment Research Council (NERC) Geophysical Equipment Facility loan 986. Logistical field support was provided by D. Heffler, D. Simpson, and residents of Nova Scotia and New Brunswick. Data for Portable Observatories for Lithospheric Analysis and Research Investigating Seismicity (POLARIS) and Canadian National Seismograph Network stations were downloaded from the Canadian National Data Centre. POLARIS stations were funded by the Canadian Foundation for Innovation, Natural Resources Canada and Industry Canada. FD is supported by Natural Sciences and Engineering Research Council of Canada through the Discovery Grants and Canada Research Chair programmes. AB is funded by the NERC Doctoral Training Partnership: Science and Solutions for a Changing Planet. We thank Thomas Plenefisch and an anonymous reviewer for their comments on this manuscript.Peer reviewedPublisher PD