America Bulletin Research Articles

Synthesis and Ion Conduction Properties of Rb3AlF6-Na3AlF6 Solid Solution

IntroductionInorganic solid electrolytes in which ions can smoothly migrate are actively studied for the development of all-solid-state batteries. Recently, fluoride-based solid electrolytes are attracting attention because of their high electrochemical stability1. Previous studies have shown that the solid solution of Li3AlF6-Li2SiF6 has a relatively high Li+ conductivity. The charge-discharge properties of all-solid-state batteries with Li3AlF6-Li2SiF6 electrolytes were excellent2. However, due to the uneven distribution and supply instability of lithium, attention has turned to sodium, which is more abundant metal in earth3. In this study, Na+ conductivity of Na3AlF6, which has the same composition with Li3AlF6 is investigated. It is known that Na3AlF6 undergoes a phase transition from monoclinic to cubic at 570°C, which improves the conductivity4.Hence, if the cubic Na3AlF6 is stabilized, high Na+ conductivity at lower temperature is expected. It has been reported that Rb3AlF6 also has the cubic polymorph5. In this study, Na3AlF6 is doped to cubic Rb3AlF6 with the aim of stabilizing cubic Na3AlF6. If the Na concentration in Rb3AlF6-Na3AlF6 solid solution exceeds 50 mol%, it is said that cubic Na3AlF6 is stabilized. The solubility limit of Rb3AlF6-Na3AlF6 is investigated and the occupancies of Rb sites in cubic Rb3AlF6 are determined. The compositional dependence of the conductivity of Na-doped Rb3AlF6 was investigated.Experimental MethodsRb3AlF6 was synthesized by planetary ball milling. RbF (SIGMA-ALDRICH 99.8%) and AlF3 (HIGH PURITY CHEMICALS) were mixed in a molar ratio of 3:1 in the glove box. The mixed powder was sealed in ZrO2 milling vessel with 10 pieces of balls. Ball-milling was performed at 400rpm for 50 hours.Na3AlF6 was prepared by melting. Rb3AlF6- Na3AlF6 solid solutions were prepared by ball-milling by mixing a given molar ratio of Rb3AlF6 and Na3AlF6. To investigate the crystal structure of the samples, XRD measurements were performed with Cu-Kα radiation source (MiniFlex, Rigaku Co.). The crystal structures of Rb3AlF6-Na3AlF6 were refined by Rietveld analysis using PDXL software (Rigaku Co.)To introduce Na vacancies, Na2SiF6 was added to the Rb3AlF6-Na3AlF6 solid solution by planetary ball milling. For the conductivity measurement, the sample was grounded and pelletized at about450 MPa in the PEEK cylinder. The impedance was measured in a frequency range between 1 MHz to 1 Hz.Results and discussionsAs shown in Figure 1(a), Rb3AlF6 synthesized by planetary ball milling showed the cubic diffraction pattern with the space group of Fm-3m. From the previous report, the stable phase of Rb3AlF6 was orthorhombic5. Hence, it is said that the cubic Rb3AlF6 obtained in this study is the meta-stable phase.The compositional dependence of the lattice volumes of Rb3AlF6-Na3AlF6 is presented in Figure (b). The Rb3AlF6 lattice size was decreased with increasing Na composition, which remained unchanged above 50 mol%. Hence, the solubility limit of Na would be 50 mol%. The shrinkage of Rb3AlF6 lattice is possibly due to the difference of the ionic radii of Na=1.02 Å and Rb=1.52 Å6. As shown in the inset of Figure 1(c), there are two types of Rb sites in cubic Rb3AlF6; Rb1 (1/4, 1/4, 1/4) (yellow) and six-coordinated Rb2 (0 , 0 , 1/2)(magenta). Rietveld analysis was performed to determine the occupancies of Rb1 and Rb2 (Occ Rb1 and Occ Rb2, respectively) for each Na composition. As shown in Figure (c), both Occ Rb1 and Occ Rb2 decreased with Na concentration, however, the Na substitution was not even among two Rb sites. The substitution preferentially occurred for Rb2 site. For 25 mol% Na3AlF6, Occ Rb2 was decreased to 0.136 while Occ Rb1 was almost unchanged. Na+ ions occupied Rb1 site after completing the substitution of Rb2 site.As a result of conductivity measurement, the sample with Rb3AlF6-Na3AlF6 -Na2SiF6 of 2:1:3 had the maximum conductivity of 4.65x10-7S/cm at 30℃. AcknowledgementThis work was supported by the NGK Environment Innovation Laboratory and JSPS KAKENHI Grant JP23H23447.(1) Feinauer, M ,et al.ACS Applied Energy Materials 2019, 2 (10), 7196-7203.(2) Maekawa.H ,et al.J. Am. Chem. Soc. 2009 . 131, 895.(3) Karl K Turekian ,et al.Geological Society of America Bulletin 1961, 72, 175-192.(4) Jansen, H ,et al.Mat. Res. Bull. 1987, 22, 887-894.(5) Rakhmatullin, A ,et al.Inorg Chem 2020, 59 (9), 6308-6318.(6)Shannon. R. D. ,et al.Acta Cryst. 1975, A32.751 Figure 1

Influence Of Lithospheric Scale Basement Faults On Seismicity In The Himalayan Orogenic System

The Himalayan system is the result of a continental collision that occurred approximately 55 million years ago between the Indian and Asian tectonic plates1,2. The collision resulted in the underthrust of the Indian crust beneath Asia, and a deformed crustal wedge3,4. The Indian plate records a complex pre-Himalayan geological history that includes several basement faults that reach depths of 70 kilometres and are oriented at a high angle to the Himalayan front5. These basement faults bound topographic basement highs that are interpreted to limit the rupture of Himalayan earthquakes6. Recent research suggests the basement faults control the distribution and magnitude of seismicity along the Himalaya7. 
 The Himalayan system serves as a prototype for novel three-dimensional numerical modelling to understand if and how inherited basement structures influence seismicity in orogenic settings. Models are generated using the Coreform Cubit meshing software and are run on the supercomputer platform hosted at the University of Toronto. The initial model contains three crustal blocks: the Indian crust, a deformed orogenic wedge, and the Asian crust, all cut at a high angle by a lithospheric scale basement fault. The 2015 7.9 MW Gorkha earthquake is simulated, and slip is generated along the Himalayan basal detachment. Seismograms, shear wave potential, and compressional wave potential movies are created to understand if and how the inherited basement faults influence seismicity within orogenic systems. Understanding how these regionally significant basement faults influence seismicity in the densely populated regions of northern India and Nepal is of utmost societal importance. 
 References 
 1. Najman, Y., et al., (2010). Timing of India‐Asia collision: Geological, biostratigraphic, and palaeomagnetic constraints. Journal of Geophysical Research: Solid Earth, 115. 
 2. Hodges, K. V. (2000). Tectonics of the Himalaya and southern Tibet from two perspectives. Geological Society of America Bulletin, 112(3), 324-350. 
 3. Godin, L., et al., (2019). Influence of inherited Indian basement faults on the evolution of the Himalayan Orogen, in Crustal Architecture and Evolution of the Himalayan-Karakoram-Tibet Orogen, R. Sharma, I. M. Villa, and S. Kumar, Editors, Geological Society of London Special Publication, 481, 251-276. 
 4. Chung, S.-L. et al. (2005). Tibetan tectonic evolution inferred from spatial and temporal variations in post-collisional magmatism. Earth-Science Reviews 68, 173–196. 
 5. Godin, L., & Harris, L. B. (2014). Tracking basement cross-strike discontinuities in the Indian crust beneath the Himalayan orogen using gravity data – relationship to upper crustal faults. Geophysical Journal International, 198, 198-215. 
 6. Gahalaut, V. K., & Kundu, B. (2012). Possible influence of subducting ridges on the Himalayan arc and on the ruptures of great and major Himalayan earthquakes. Gondwana Research, 21(4), 1080-1088. 
 7. Gahalaut, V, K., & Arora, B. R. (2012). Segmentation of seismicity along the Himalayan Arc due to structural heterogeneities in the under-thrusting Indian plate and overriding Himalayan wedge. Episodes Journal of International Geoscience, 35(4), 493-500.

SHRIMP U–Pb geochronology of Mesoproterozoic basement and overlying Ocoee Supergroup, NC–TN: dating diagenetic xenotime and monazite overgrowths on detrital minerals to determine the age of sedimentary deposition

Sedimentary rocks of the Ocoee Supergroup crop out in the Appalachian Blue Ridge of western North Carolina and eastern Tennessee. This ∼12 km thick sequence of strata was mapped as nonconformably overlying Mesoproterozoic crystalline basement (about 1.20–1.02 Ga) and beneath the lower Cambrian Chilhowee Group, leading to the traditional interpretation that the Ocoee Supergroup was deposited between about 1.02 and 0.54 Ga. This interpretation was challenged by Unrug and Unrug (1990, Geology, 18: 1041–1045) and Unrug et al. (2000, Geological Society of America Bulletin. Vol. 112, pp. 982–996), who claimed that Paleozoic fossils were recovered from rocks of the Walden Creek Group (upper Ocoee), and thereby created a new tectonic model for the origin of Laurentia. To resolve the age controversy concerning the time of deposition of the Ocoee Supergroup, diagenetic xenotime overgrowths on detrital zircon and diagenetic monazite on detrital monazite were dated by the U–Pb method. Sensitive High Resolution Ion Microprobe ages of diagenetic xenotime from three samples of sandstone (Thunderhead Sandstone, Cades Sandstone, and Shields Formation) indicate that the Ocoee Supergroup was deposited in the interval of about 580–550 Ma. A sample of Sandsuck Formation (uppermost Ocoee) yielded xenotime overgrowths of about 410 Ma, probably related to post-depositional low-grade metamorphism. Various origins of xenotime overgrowths may be distinguished by trace element distributions. Ages and trace element concentrations of monazite overgrowths support the xenotime age results, although concordia systematics are complicated by high concentrations of common Pb and inheritance of ages (∼1.2 and 0.6 Ga). These age data support the observed field relations for a late Neoproterozoic depositional age of the Ocoee Supergroup.

Petrography, geochemistry and tectonic setting of adakitic bodies in the Tighanab area and their relationship with iron skarn mineralization (southeast of Sarbisheh-east of Iran)

Petrography, geochemistry and tectonic setting of adakitic bodies in the Tighanab area and their relationship with iron skarn mineralization (southeast of Sarbisheh-east of Iran)

Subduction Polarity in Ancient Arcs: A Call to Integrate Geology and Geophysics to Decipher the Mesozoic Tectonic History of the Northern Cordillera of North America: REPLY

Subduction Polarity in Ancient Arcs: A Call to Integrate Geology and Geophysics to Decipher the Mesozoic Tectonic History of the Northern Cordillera of North America: REPLY

Special issue of MAPS in honor of Wolf Uwe Reimold on occasion of his 65th birthday

Special issue of <i>MAPS</i> in honor of Wolf Uwe Reimold on occasion of his 65th birthday

Transmission and Reflection of Fundamental‐ModeRgSignals from Atmospheric and Underground Explosions

Research Article| September 18, 2018 Transmission and Reflection of Fundamental‐Mode Rg Signals from Atmospheric and Underground Explosions Vanessa J. Napoli; Vanessa J. Napoli aWeston Geophysical Corp., 181 Bedford St. Suite 1, Lexington, Massachusetts 02420, vnapoli@westongeo.comdhrussell@westongeo.com Search for other works by this author on: GSW Google Scholar David R. Russell David R. Russell aWeston Geophysical Corp., 181 Bedford St. Suite 1, Lexington, Massachusetts 02420, vnapoli@westongeo.comdhrussell@westongeo.combAlso at 275 Wilson Avenue, Satellite Beach, Florida 32937. Search for other works by this author on: GSW Google Scholar Author and Article Information Vanessa J. Napoli aWeston Geophysical Corp., 181 Bedford St. Suite 1, Lexington, Massachusetts 02420, vnapoli@westongeo.comdhrussell@westongeo.com David R. Russell aWeston Geophysical Corp., 181 Bedford St. Suite 1, Lexington, Massachusetts 02420, vnapoli@westongeo.comdhrussell@westongeo.combAlso at 275 Wilson Avenue, Satellite Beach, Florida 32937. Publisher: Seismological Society of America First Online: 18 Sep 2018 Online Issn: 1943-3573 Print Issn: 0037-1106 © Seismological Society of America Bulletin of the Seismological Society of America (2018) 108 (6): 3590–3597. https://doi.org/10.1785/0120180084 Article history First Online: 18 Sep 2018 Cite View This Citation Add to Citation Manager Share Icon Share Facebook Twitter LinkedIn MailTo Tools Icon Tools Get Permissions Search Site Citation Vanessa J. Napoli, David R. Russell; Transmission and Reflection of Fundamental‐Mode Rg Signals from Atmospheric and Underground Explosions. Bulletin of the Seismological Society of America 2018;; 108 (6): 3590–3597. doi: https://doi.org/10.1785/0120180084 Download citation file: Ris (Zotero) Refmanager EasyBib Bookends Mendeley Papers EndNote RefWorks BibTex toolbar search Search Dropdown Menu toolbar search search input Search input auto suggest filter your search All ContentBy SocietyBulletin of the Seismological Society of America Search Advanced Search Abstract Rg signals measured between 1 and 5 Hz at local and near‐regional distances provide a viable method for estimating the yields of atmospheric and underground explosions. However, tested methods have been restricted to single or slowly changing source and receiver geologies, because propagation across abruptly changing geological boundaries can cause large reflections of the propagating Rg signals resulting in unacceptably large errors in yield estimates. In this article, we demonstrate how to correct for transmission and reflection across boundaries if estimates of the layered velocity, density, and attenuation structure in the different geological media are known. The methodology developed is tested using the alluvium and limestone structures analyzed in detail for the Humble Redwood (HR) III (2012) explosions conducted near Albuquerque, New Mexico. We validate the technique against the HRI (2007) and HRII (2009) atmospheric and underground explosions conducted in the same geologies as HRIII, with propagation paths crossing both alluvium and limestone. We compare synthetic estimates of yields of the HRI and HRII explosions based on earth structure to the known yield of 540 kg for these events. With no alluvium–limestone transmission correction, the estimated yield for the atmospheric explosion is 31 kg, and underground is 53 kg, which are both grossly inaccurate. The estimated yield after applying the transmission correction for the atmospheric explosion is 590 kg, and for the underground explosion is 617 kg, giving respective yield errors of 9% and 14%. You do not have access to this content, please speak to your institutional administrator if you feel you should have access.

Relative Moment Tensor Inversion with Application to Shallow Underground Explosions and Earthquakes

Research Article| August 14, 2018 Relative Moment Tensor Inversion with Application to Shallow Underground Explosions and Earthquakes Anastasia Stroujkova Anastasia Stroujkova aWeston Geophysical Corp., 181 Bedford Street Suite 1, Lexington, Massachusetts 02420, ana@westongeo.com Search for other works by this author on: GSW Google Scholar Author and Article Information Anastasia Stroujkova aWeston Geophysical Corp., 181 Bedford Street Suite 1, Lexington, Massachusetts 02420, ana@westongeo.com Publisher: Seismological Society of America First Online: 14 Aug 2018 Online Issn: 1943-3573 Print Issn: 0037-1106 © Seismological Society of America Bulletin of the Seismological Society of America (2018) 108 (5A): 2724–2738. https://doi.org/10.1785/0120180082 Article history First Online: 14 Aug 2018 Cite View This Citation Add to Citation Manager Share Icon Share Facebook Twitter LinkedIn MailTo Tools Icon Tools Get Permissions Search Site Citation Anastasia Stroujkova; Relative Moment Tensor Inversion with Application to Shallow Underground Explosions and Earthquakes. Bulletin of the Seismological Society of America 2018;; 108 (5A): 2724–2738. doi: https://doi.org/10.1785/0120180082 Download citation file: Ris (Zotero) Refmanager EasyBib Bookends Mendeley Papers EndNote RefWorks BibTex toolbar search Search Dropdown Menu toolbar search search input Search input auto suggest filter your search All ContentBy SocietyBulletin of the Seismological Society of America Search Advanced Search Abstract Single‐source moment tensor (MT) techniques require calculation of the Green’s functions. This limits applicability of the approach to low frequencies because Green’s function calculations are very sensitive to media heterogeneities, especially at high frequencies. Relative moment tensor inversion (RMTI) developed by Dahm (1996) eliminates the need for calculation of the Green’s functions. In this article, the RMTI method is modified to perform MT inversion for a group of closely located shallow seismic events (e.g., underground explosions) by incorporating amplitudes for short‐period fundamental‐mode Rayleigh waves (Rg). The main benefits of the modified method are (1) it can be used in any frequency range provided the signal‐to‐noise ratio is high enough in that range, and (2) the method allows the calculation of the Green’s functions in any frequency range, self‐consistently, after the MT inversion is complete. The robustness of the approach for MT inversion and Green’s function estimation for the small shallow events was tested using synthetic data as well as a small chemical explosion dataset (e.g., Stroujkova et al., 2017). You do not have access to this content, please speak to your institutional administrator if you feel you should have access.

Petrology, geochemistry, and Sr, Nd isotopes of mantle xenolith in Nghia Dan alkaline basalt (West Nghe An): implications for lithospheric mantle characteristics beneath the region

Petrology, geochemistry, and Sr, Nd isotopes of mantle xenolith in Nghia Dan alkaline basalt (West Nghe An): implications for lithospheric mantle characteristics beneath the region

ShakingAlarm: A Nontraditional Regional Earthquake Early Warning System Based on Time‐Dependent Anisotropic Peak Ground‐Motion Attenuation Relationships

Research Article| April 03, 2018 ShakingAlarm: A Nontraditional Regional Earthquake Early Warning System Based on Time‐Dependent Anisotropic Peak Ground‐Motion Attenuation Relationships Benjamin Ming Yang; Benjamin Ming Yang aDepartment of Geosciences, National Taiwan University, No. 1, Sec. 4, Roosevelt Road, Taipei 10617, Taiwan, tingchunghuang@gmail.com, yihmin.wu@gmail.com, b98204032@gmail.com Search for other works by this author on: GSW Google Scholar Ting‐Chung Huang; Ting‐Chung Huang aDepartment of Geosciences, National Taiwan University, No. 1, Sec. 4, Roosevelt Road, Taipei 10617, Taiwan, tingchunghuang@gmail.com, yihmin.wu@gmail.com, b98204032@gmail.combAlso at Institute of Earth Sciences, Academia Sinica 128, Section 2, Academia Road, Nangang, Taipei 11529, Taiwan. Search for other works by this author on: GSW Google Scholar Yih‐Min Wu Yih‐Min Wu aDepartment of Geosciences, National Taiwan University, No. 1, Sec. 4, Roosevelt Road, Taipei 10617, Taiwan, tingchunghuang@gmail.com, yihmin.wu@gmail.com, b98204032@gmail.combAlso at Institute of Earth Sciences, Academia Sinica 128, Section 2, Academia Road, Nangang, Taipei 11529, Taiwan. Search for other works by this author on: GSW Google Scholar Author and Article Information Benjamin Ming Yang aDepartment of Geosciences, National Taiwan University, No. 1, Sec. 4, Roosevelt Road, Taipei 10617, Taiwan, tingchunghuang@gmail.com, yihmin.wu@gmail.com, b98204032@gmail.com Ting‐Chung Huang aDepartment of Geosciences, National Taiwan University, No. 1, Sec. 4, Roosevelt Road, Taipei 10617, Taiwan, tingchunghuang@gmail.com, yihmin.wu@gmail.com, b98204032@gmail.combAlso at Institute of Earth Sciences, Academia Sinica 128, Section 2, Academia Road, Nangang, Taipei 11529, Taiwan. Yih‐Min Wu aDepartment of Geosciences, National Taiwan University, No. 1, Sec. 4, Roosevelt Road, Taipei 10617, Taiwan, tingchunghuang@gmail.com, yihmin.wu@gmail.com, b98204032@gmail.combAlso at Institute of Earth Sciences, Academia Sinica 128, Section 2, Academia Road, Nangang, Taipei 11529, Taiwan. Publisher: Seismological Society of America First Online: 03 Apr 2018 Online Issn: 1943-3573 Print Issn: 0037-1106 © Seismological Society of America Bulletin of the Seismological Society of America (2018) 108 (3A): 1219–1230. https://doi.org/10.1785/0120170105 Article history First Online: 03 Apr 2018 Cite View This Citation Add to Citation Manager Share Icon Share Facebook Twitter LinkedIn MailTo Tools Icon Tools Get Permissions Search Site Citation Benjamin Ming Yang, Ting‐Chung Huang, Yih‐Min Wu; ShakingAlarm: A Nontraditional Regional Earthquake Early Warning System Based on Time‐Dependent Anisotropic Peak Ground‐Motion Attenuation Relationships. Bulletin of the Seismological Society of America 2018;; 108 (3A): 1219–1230. doi: https://doi.org/10.1785/0120170105 Download citation file: Ris (Zotero) Refmanager EasyBib Bookends Mendeley Papers EndNote RefWorks BibTex toolbar search Search Dropdown Menu toolbar search search input Search input auto suggest filter your search All ContentBy SocietyBulletin of the Seismological Society of America Search Advanced Search Abstract The P‐alert seismic network, an on‐site low‐cost earthquake early warning system (EEWS) located in Taiwan, has proven useful in earthquake events since 2010. This dense network can produce detailed shakemaps and identify the direction of the source rupture in near‐real time. Based on real‐time acceleration signals and the proposed time‐dependent anisotropic attenuation relationship with peak ground acceleration (PGA), ShakingAlarm, a regional early warning system add‐on to the original P‐alert network, can immediately provide (1) an accurate predicted PGA, before the arrival of the observed PGA, that will give a consistent lead time for hazard assessment and emergency response, (2) a predicted shakemap (PSM) that will converge faster to the final reported shakemap than the regional EEWS, and (3) a shake contour area‐based magnitude estimation that is robust, even in the absence of a measured shake contour area such as in the case of an offshore earthquake. Taking the 2016 Mw 6.4 Meinong earthquake as an example, the 14th second PSM from ShakingAlarm converges on the final shakemap better than the regional EEWS from the Central Weather Bureau (CWB) in Taiwan. According to our tests, ShakingAlarm provides a warning using modified Mercalli intensity (MMI) V that is consistent with the results of another on‐site EEWS (Strategies and Tools for Real Time Earthquake Risk ReducTion [REAKT]). Further performance tests were conducted with another five ML>5.5 inland earthquakes from 2013 to 2014. Compared with traditional regional EEWSs, ShakingAlarm can effectively identify possible damage regions and provide valuable early warning information (PSM, predicted PGA, and magnitude) for risk mitigation. You do not have access to this content, please speak to your institutional administrator if you feel you should have access.

Comment on “The Maximum Possible and the Maximum Expected Earthquake Magnitude for Production‐Induced Earthquakes at the Gas Field in Groningen, The Netherlands” by Gert Zöller and Matthias Holschneider

Article Commentary| February 06, 2018 Comment on “The Maximum Possible and the Maximum Expected Earthquake Magnitude for Production‐Induced Earthquakes at the Gas Field in Groningen, The Netherlands” by Gert Zöller and Matthias Holschneider Mathias Raschke Mathias Raschke aStolze‐Schrey‐Straße1, 65195 Wiesbaden, Germany, mathiasraschke@t-online.de Search for other works by this author on: GSW Google Scholar Author and Article Information Mathias Raschke aStolze‐Schrey‐Straße1, 65195 Wiesbaden, Germany, mathiasraschke@t-online.de Publisher: Seismological Society of America First Online: 06 Feb 2018 Online Issn: 1943-3573 Print Issn: 0037-1106 © Seismological Society of America Bulletin of the Seismological Society of America (2018) 108 (2): 1025–1028. https://doi.org/10.1785/0120170100 Article history First Online: 06 Feb 2018 Cite View This Citation Add to Citation Manager Share Icon Share Facebook Twitter LinkedIn MailTo Tools Icon Tools Get Permissions Search Site Citation Mathias Raschke; Comment on “The Maximum Possible and the Maximum Expected Earthquake Magnitude for Production‐Induced Earthquakes at the Gas Field in Groningen, The Netherlands” by Gert Zöller and Matthias Holschneider. Bulletin of the Seismological Society of America 2018;; 108 (2): 1025–1028. doi: https://doi.org/10.1785/0120170100 Download citation file: Ris (Zotero) Refmanager EasyBib Bookends Mendeley Papers EndNote RefWorks BibTex toolbar search Search Dropdown Menu toolbar search search input Search input auto suggest filter your search All ContentBy SocietyBulletin of the Seismological Society of America Search Advanced Search Abstract Zöller and Holschneider (2016) focused on distribution of the earthquake maximum magnitude of the gas field in Groningen, The Netherlands, and applied the predictive distribution. They incorrectly used the term Bayesian posterior probability density function because it is a term of the Bayesian parameter inference and not for the predictive distribution of a random variable. As explained here, the approach of the predictive distribution can be applied on Bayesian and frequentist inference. However, it is not a useful and stable approach. The original intention of the approach was a model test and not an actual prediction. The authors did not use the approach consequently because they did not consider the uncertainty of all parameters. Besides, the distribution of the maximum magnitude does not include more information than the magnitude frequency function (Gutenberg–Richter relation). Additionally, the state‐of‐the‐art of mathematical statistics includes more methods for the upper bound magnitude (maximum possible earthquake magnitude), than considered by Zöller and Holschneider (2016). Uncertainty quantification is possible for these estimators, in contrast to the statement of the authors. At the end of their analysis, they used the 90% percentile (confidence level) as point estimation for the upper bound magnitude. The selection of 90% is debatable. The most recent point estimation of Beirlant et al. (2017) for the upper bound leads to a distribution of the maximum earthquake magnitude which is very different from the results of Zöller and Holschneider (2016). You do not have access to this content, please speak to your institutional administrator if you feel you should have access.

Comment on “Unbiased Estimation of Moment Magnitude from Body‐ and Surface‐Wave Magnitudes,” by R. Das, H. R. Wason, and M. L. Sharma, and “Comparative Analysis of Regression Methods Used for Seismic Magnitude Conversions” by P. Gasperini, B. Lolli, and S. Castellaro

Article Commentary| November 14, 2017 Comment on “Unbiased Estimation of Moment Magnitude from Body‐ and Surface‐Wave Magnitudes,” by R. Das, H. R. Wason, and M. L. Sharma, and “Comparative Analysis of Regression Methods Used for Seismic Magnitude Conversions” by P. Gasperini, B. Lolli, and S. Castellaro J. Pujol J. Pujol Search for other works by this author on: GSW Google Scholar Author and Article Information J. Pujol Publisher: Seismological Society of America First Online: 14 Nov 2017 Online Issn: 1943-3573 Print Issn: 0037-1106 © Seismological Society of America Bulletin of the Seismological Society of America (2018) 108 (1): 533–539. https://doi.org/10.1785/0120160176 Article history First Online: 14 Nov 2017 Cite View This Citation Add to Citation Manager Share Icon Share Facebook Twitter LinkedIn MailTo Tools Icon Tools Get Permissions Search Site Citation J. Pujol; Comment on “Unbiased Estimation of Moment Magnitude from Body‐ and Surface‐Wave Magnitudes,” by R. Das, H. R. Wason, and M. L. Sharma, and “Comparative Analysis of Regression Methods Used for Seismic Magnitude Conversions” by P. Gasperini, B. Lolli, and S. Castellaro. Bulletin of the Seismological Society of America 2017;; 108 (1): 533–539. doi: https://doi.org/10.1785/0120160176 Download citation file: Ris (Zotero) Refmanager EasyBib Bookends Mendeley Papers EndNote RefWorks BibTex toolbar search Search Dropdown Menu toolbar search search input Search input auto suggest filter your search All ContentBy SocietyBulletin of the Seismological Society of America Search Advanced Search Because the conversion between different types of magnitudes is frequently an essential component to seismotectonic and seismic hazard studies, it is important to understand the advantages and limitations of different conversion methods that have been proposed in the literature. In fact, there is an aspect of the conversion that is the matter of current debate, which can be summarized as follows. Given two sets of different types of magnitudes, the conversion generally takes the form of a linear relation between the two magnitudes. As both magnitudes are affected by errors, this relation is obtained using regression techniques that take into... You do not have access to this content, please speak to your institutional administrator if you feel you should have access.

Assessment of earthquake-induced ground liquefaction susceptibility for Hanoi city using geological and geomorphologic characteristics

Assessment of earthquake-induced ground liquefaction susceptibility for Hanoi city using geological and geomorphologic characteristics

Delayed recognition of geomorphology papers in the Geological Society of America Bulletin

The Geological Society of America Bulletin was an early home for quantitative geomorphology research. Although geomorphology papers are not uniformly the highest cited papers in the Bulletin, many show ‘delayed recognition’—they garner only few citations directly after publication, before suddenly being widely and numerously cited (sometimes decades after publication). I focus here on (1) algorithmically detecting cases of delayed recognition in geomorphology literature from the Bulletin and (2) providing insight into why delayed recognition occurred for these papers.

A theoretical analysis of basin-scale groundwater temperature distribution

The theory of regional groundwater flow is critical for explaining heat transport by moving groundwater in basins. Domenico and Palciauskas’s (1973) pioneering study on convective heat transport in a simple basin assumed that convection has a small influence on redistributing groundwater temperature. Moreover, there has been no research focused on the temperature distribution around stagnation zones among flow systems. In this paper, the temperature distribution in the simple basin is reexamined and that in a complex basin with nested flow systems is explored. In both basins, compared to the temperature distribution due to conduction, convection leads to a lower temperature in most parts of the basin except for a small part near the discharge area. There is a high-temperature anomaly around the basin-bottom stagnation point where two flow systems converge due to a low degree of convection and a long travel distance, but there is no anomaly around the basin-bottom stagnation point where two flow systems diverge. In the complex basin, there are also high-temperature anomalies around internal stagnation points. Temperature around internal stagnation points could be very high when they are close to the basin bottom, for example, due to the small permeability anisotropy ratio. The temperature distribution revealed in this study could be valuable when using heat as a tracer to identify the pattern of groundwater flow in large-scale basins. Domenico PA, Palciauskas VV (1973) Theoretical analysis of forced convective heat transfer in regional groundwater flow. Geological Society of America Bulletin 84:3803–3814

Fossil snail shells tell story about Tibetan Plateau

Ancient and modern snail shells have given scientists a unique look at the evolution of the Tibetan Plateau, confirming that parts of the plateau have actually lost elevation over time, despite its immense height. A new paper detailing the research was published on 29 August in the Geological Society of America Bulletin (doi:10.1130/B31000.1).

Washburn AL (1956) Classification of patterned ground and review of suggested origins. Geological Society of America Bulletin 67(7): 823–865.

Washburn AL (1956) Classification of patterned ground and review of suggested origins. <i>Geological Society of America Bulletin</i> 67(7): 823–865.

Cominco American well: Implications for the reconstruction of the Sevier orogen and basin and range extension in west-central Utah

Re-evaluation of acoustic, gamma ray and dip meter logs from the Cominco American Federal No. 2 well in the Sevier Desert basin of west-central Utah sheds new light on the interpretation of Neoproterozoic and Cambrian stratigraphy and Mesozoic structure in a region that has been influential in the development of ideas about crustal shortening and extension. The most prominent of several major thrust faults (the Canyon Range and Pavant thrusts) have been interpreted by DeCelles and Coogan (2006) [Regional structure and kinematic history of the Sevier fold-and-thrust belt, central Utah: Geological Society of America Bulletin, v. 118, n. 7-8, p. 841-864, http://dx.doi.org/10.1130/B25759.1] as having been cut and in part re-activated between late Oligocene and Holocene time by as much as 47 km of displacement on the gently west-dipping Sevier Desert detachment. This interpretation, which is based upon a combination of outcrop, seismic reflection and well data, depends critically on the Canyon Range thrust intersecting the Cominco well at a depth of 2,551 to 2,557 m (8,370-8,389 ft.), and terminating downwards against a re-activated Pavant thrust. Our work suggests that the fault at 2,551 m (8,370 ft.) is a strand of the Pavant thrust, and that the Canyon Range thrust cuts the well at a depth of 1,222 m (4,010 ft.). This alternative interpretation depends in turn on identification of the section between the two faults as terminal Neoproterozoic to middle Cambrian Prospect Mountain Quartzite through Chisholm Formation rather than Neoproterozoic “Pocatello Formation,” “Blackrock Canyon Limestone” and lower Caddy Canyon Quartzite. To support this interpretation we present evidence for stratigraphic repetition and for deformation at the 1,222 m (4,010 ft.) level. Use of the lithostratigraphic terms “Pocatello” and “Blackrock Canyon” in west-central Utah is shown to be inappropriate, and among the reasons that the critical interval in the Cominco well has been misinterpreted by some authors. If the Canyon Range and Pavant thrusts are both found in the Cominco well, as we suggest, then they cannot be used as a piercing point for the estimation of displacement on the Sevier Desert detachment or as justification for the existence of the detachment. Published estimates of extension across the Sevier Desert basin therefore need to be reduced, potentially to as little as ∼10 km.

Resolution of Respect: Professor Paul Schultz Martin 1928–2010

Resolution of Respect: Professor Paul Schultz Martin 1928–2010

A rational sediment transport scaling relation based on dimensionless stream power

AbstractThe concept of stream channel grade – according to which a stream channel reach will adjust its gradient, S, in order to transport the imposed sediment load having magnitude Qb and characteristic grain size Db, with the available discharge Q (Mackin, 1948, Geological Society of America Bulletin 59: 463–512; Lane, 1955, American Society of Civil Engineers, Proceedings 81: 1–17) is one of the most influential ideas in fluvial geomorphology. Herein, we derive a scaling relation that describes how externally imposed changes in either Qb or Q can be accommodated by changes in the channel configuration, described by the energy gradient, mean flow depth, characteristic grain size and a parameter describing the effect of bed surface structures on grain entrainment. One version of this scaling relation is based on the dimensionless bed material transport parameter (W*) presented by Parker and Klingeman (1982, Water Resources Research 18: 1409–1423). An equivalent version is based on a new dimensionless transport parameter (E*) using dimensionless unit stream power. This version is nearly identical to the relation based on W*, except that it is independent of flow resistance. Both versions of the scaling relation are directly comparable to Lane's original relation. In order to generate this stream power‐based scaling relation, we derived an empirical transport function relation relating E* to dimensionless stream power using data from a wide range of stable, bed load‐dominated channels: the form of that transport function is based on the understanding that, while grain entrainment is related to the forces acting on the bed (described by dimensionless shear stress), sediment transport rate is related to the transfer of momentum from the fluid to the bed material (described by dimensionless stream power). Copyright © 2010 John Wiley &amp; Sons, Ltd.