The impact of earthquake cycle variability on neotectonic and paleoseismic slip rate estimates

Because of the natural (aleatoric) variability in earthquake recurrence intervals and coseismic displacements on a fault, cumulative slip on a fault does not increase linearly or perfectly step-wise with time; instead, some amount of variability in shorter-term slip rates results. Though this variability could greatly affect the accuracy of neotectonic (i.e., late Quaternary) and paleoseismic slip rate estimates, these effects have not been quantified. In this study, idealized faults with four different, representative, earthquake recurrence distributions are created with equal mean recurrence intervals (1000 years) and coseismic slip distributions, and the variability in slip rate estimates over 500- to 100&thinsp;000-year measurement windows is calculated for all faults through Monte Carlo simulations. Slip rates are calculated as net offset divided by elapsed time, as in a typical neotectonic study. The recurrence distributions used are quasi-periodic, unclustered and clustered lognormal distributions, and an unclustered exponential distribution. The results demonstrate that the most important parameter is the coefficient of variation (CV =&thinsp;standard deviation&thinsp;∕&thinsp;mean) of the recurrence distributions rather than the shape of the distribution itself. Slip rate variability over short timescales (&lt;&thinsp;5000 years or 5 mean earthquake cycles) is quite high, varying by a factor of 3 or more from the mean, but decreases with time and is close to stable after ∼40 000 years (40 mean earthquake cycles). This variability is higher for recurrence distributions with a higher CV. The natural variability in the slip rate estimates compared to the true value is then used to estimate the epistemic uncertainty in a single slip rate measurement (as one would make in a geological study) in the absence of any measurement uncertainty. This epistemic uncertainty is very high (a factor of 2 or more) for measurement windows of a few mean earthquake cycles (as in a paleoseismic slip rate estimate), but decreases rapidly to a factor of 1–2 with &gt;&thinsp;5 mean earthquake cycles (as in a neotectonic slip rate study). These uncertainties are independent of, and should be propagated with, uncertainties in fault displacement and geochronologic measurements used to estimate slip rates. They may then aid in the comparison of slip rates from different methods or the evaluation of potential slip rate changes over time.</p

Thermochronologic constraints on the late Cenozoic exhumation history of the Gurla Mandhata metamorphic core complex, Southwestern Tibet

This is the publisher's version, also available electronically from http://onlinelibrary.wiley.com/doi/10.1002/2013TC003302/abstractHow the Tibetan plateau is geodynamically linked to the Himalayas is a topic receiving considerable attention. The Karakoram fault plays key roles in describing the structural relationship between southern Tibet and the Himalayas. In particular, considerable debate exists at the southeastern end of the Karakoram fault, where its role is interpreted in two different ways. One interpretation states that slip along the dextral Karakoram fault extends eastward along the Indus-Yalu suture zone, bypassing the Himalayas. The other interprets that fault slip is fed southward into the Himalayan thrust belt along the Gurla Mandhata detachment (GMD). To evaluate these competing models, the late Miocene history of the GMD was reconstructed from thermokinematic modeling of zircon (U-Th)/He data. Three east-west transects reveal rapid cooling of the GMD footwall from 8.0 ± 1.3 Ma to 2.6 ± 0.7 Ma. Model simulations show a southward decrease in slip magnitude and rate along the GMD. In the north, initiation of the GMD range between 14 and 11 Ma with a mean fault slip rate of 5.0 ± 0.9 mm/yr. The central transect shows an initiation age from 14 to 11 Ma with a mean fault slip rate of 3.3 ± 0.6 mm/yr. In the south, initiation began between 15 and 8 Ma with a mean fault slip rate of 3.2 ± 1.6 mm/yr. The initiation ages and slip rates match the Karakoram fault across several timescales, supporting the idea that the two are kinematically linked. Specifically, the data are consistent with the GMD acting as an extensional stepover, with slip transferred southward into the Himalayas of western Nepal

Is There Such a Thing as Psychological Pain? and Why It Matters

Medicine regards pain as a signal of physical injury to the body despite evidence contradicting the linkage and despite the exclusion of vast numbers of sufferers who experience psychological pain. By broadening our concept of pain and making it more inclusive, we would not only better accommodate the basic science of pain but also would recognize what is already appreciated by the layperson—that pain from diverse sources, physical and psychological, share an underlying felt structure

Individual Preferences and Social Interactions Determine the Aggregation of Woodlice

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Cost benefit analysis of General Services Administration's proposed relocation

General Services Administration is faced with the responsibility of improving its physical distribution capabilities by either upgrading its current facilities or constructing a new facility. A cost/benefit analysis was conducted of all viable alternatives as to the least future cost to the government while maintaining General Services Administration's current level of service and effectiveness. Of the alternatives analyzed, it was determined that it would be of the utmost benefit to the government for General Services Administration's Western Distribution Center to relocate at Sharpe Army Depot, current site of a portion of Defense Logistics Agencies Western Distribution Center. At Sharpe, General Services Administration has the greatest potential for cost savings while improving its warehousing ability well into the next century. Additionally, there are many potential benefits not addressed, such as consolidation between General Services Administration and Defense Logistics Agency, in order to take advantage of greater cost benefits.http://archive.org/details/costbenefitanaly00asseLieutenant Commander, United States NavyApproved for public release; distribution is unlimited

Application exercise design for team-based learning in online courses

This chapter describes best practices for adapting traditional, face-to-face, team-based learning principles to develop online application exercise design, support effective facilitation, and use appropriate technology to promote effective online team collaboration. The unique challenges of online TBL applications include maintaining effective team collaboration, discussion facilitation, and simultaneous reporting. A framework is proposed to guide practitioners to make appropriate, systematic choices in the development of online TBL applications.This is the published version of the following article: Dorneich, Michael C., Brian O'Dwyer, Annetta R. Dolowitz, Jennifer L. Styron, and James Grogan. "Application exercise design for team‐based learning in online courses." New Directions for Teaching and Learning 2021, no. 165 (2021): 41-52. DOI: 10.1002/tl.20435. Copyright 2021 The Authors. Attribution-NonCommercial-NoDerivatives 4.0 International (CC BY-NC-ND 4.0). Posted with permission