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Short-period Rayleigh waves, Rg, provide strong constraints on the depth of shallow seismic events and are of interest for monitoring small explosions. Characterizing the seismic sources that generate Rg requires an understanding of how shallow crustal structure affects Rayleigh wave propagation. In support of these efforts, this study utilizes observed waveforms from small shallow explosions recorded on temporary seismic network deployments in the Bighorn region, Wyoming. We study regional near-surface geology by measuring changes in surface-wave amplitude and polarization during propagation through basins, foothills, and mountains. We develop additional insight by carrying out surface-wave eigenfunction analyses and numerical-wave simulations, which together reproduce many characteristics seen in the observed waveforms. Our results show how sedimentary basins in the Bighorn region allow for amplified prograde-polarized higher-mode and retrograde-polarized fundamental-mode Rayleigh waves, whereas adjacent mountains only support retrograde motion. These different modes provide distinct constraints on the Earth structure and source characteristics, potentially enabling targeted inversions in future studies. Our findings provide insight into Rg propagation through complex near-surface geology, improving our understanding of shallow propagation and source effects that are relevant to explosion monitoring efforts.

Recent efforts to characterize small (Mw

Hospital noise is associated with adverse effects on patients and staff. Communication through overhead paging is a major contributor to hospital noise. Replacing overhead paging with smartphones through a clinical mobility platform has the potential to reduce transitory noises in the hospital setting, though this result has not been described. The current study evaluated the impact of replacing overhead paging with a smartphone-based clinical mobility platform on transitory noise levels in a labor and delivery unit. Transitory noises were defined as sound levels greater than 10 dB above baseline, as recorded by a sound level meter. Prior to smartphone implementation, 77% of all sound levels at or above 60 dB were generated by overhead paging. Overhead pages occurred at an average rate of 3.17 per hour. Following smartphone implementation, overhead pages were eliminated and transitory noises decreased by two-thirds (P < 0.001). The highest recorded sound level decreased from 76.54 to 57.34 dB following implementation. The percent of sounds that exceeded the thresholds recommended by the Environmental Protection Agency and International Noise Council decreased from 31.2% to 0.2% following implementation (P < 0.001). Replacement of overhead paging with a clinical mobility platform that utilized smartphones was associated with a significant reduction in transitory noise. Clinical mobility implementation, as part of a noise reduction strategy, may be effective in other inpatient settings.

There are fewer evidence-based social and emotional learning programs for middle school students compared to younger grades. This randomized controlled trial tests the effectiveness of Facing History and Ourselves (hereafter, Facing History) with a sample of 694 (Facing History n = 437; Comparison n = 257) students from a low-resourced school district. Youth self-identified as female (59%), Black/African American (61%), Hispanic/Latinx (18%), White (2%), and multi-racial or some other race/ethnicity (19%). Intervention students perceived their classrooms as more caring and democratic than students in the comparison group. They reported higher levels of empathy, prosocial behavior, and stronger participatory citizenship beliefs. This study expands the evidence-based of effective SEL programs available to schools.

This study explores the effectiveness of local-distance (

Aftershocks of the 2012 Off-Coast of Sumatra Earthquake Sequence exhibit a complex and diffuse spatial distribution. The first-order complexity in aftershock distribution is clear and well beyond the influence of typical earthquake location uncertainty. The sequence included rupture of multiple fault segments, spatially separated. We use surface-wave based relative centroid locations to examine whether, at the small scale, the distribution of the aftershocks was influenced by location errors. Surface-wave based relative location has delineated precise oceanic transform fault earthquake locations in multiple regions. However, the relocated aftershocks off the coast of Sumatra seldom align along simple linear trends that are compatible with the corresponding fault strikes as estimated for the GCMT catalog. The relocation of roughly 60 moderate-earthquake epicentroids suggests that the faulting involved in the 2012 earthquake aftershock sequence included strain release along many short fault segments. Statistical analysis and temporal variations of aftershocks show a typical decay of the aftershocks but a relatively low number of aftershocks, as is common for intraplate oceanic earthquakes. Coulomb stress calculations indicate that most of the moderate-magnitude aftershocks are compatible with stress changes predicted by the large-event slip models. The patterns in the aftershocks suggest that the formation of the boundary and eventual localization of deformation between the Indian and Australian plate is a complicated process., accepted by Tectonophysics on 25 Apr 2019

We present a method to estimate precise relative magnitudes using cross correlation of seismic waveforms. Our method incorporates the intercorrelation of all events in a group of earthquakes, as opposed to individual event pairings relative to a reference event. This method works well when a reliable reference event does not exist. We illustrate the method using vertical strike‐slip earthquakes located in the northeast Pacific and Panama fracture zone regions. Our results are generally consistent with the Global Centroid Moment Tensor catalog, which we use to establish a baseline for the relative event sizes. Online Material: Supplementary description and formulation of uncertainty, and tables of relative magnitudes.

The northern Vanuatu (formerly New Hebrides) subduction zone (11°S to 14°S) has experienced large shallow thrust earthquakes with Mw > 7 in 1966 (MS 7.9, 7.3), 1980 (Mw 7.5, 7.7), 1997 (Mw 7.7), 2009 (Mw 7.7, 7.8, 7.4), and 2013 (Mw 8.0). We analyze seismic data from the latter four earthquake sequences to quantify the rupture processes of these large earthquakes. The 7 October 2009 earthquakes occurred in close spatial proximity over about 1 h in the same region as the July 1980 doublet. Both sequences activated widespread seismicity along the northern Vanuatu subduction zone. The focal mechanisms indicate interplate thrusting, but there are differences in waveforms that establish that the events are not exact repeats. With an epicenter near the 1980 and 2009 events, the 1997 earthquake appears to have been a shallow intraslab rupture below the megathrust, with strong southward directivity favoring a steeply dipping plane. Some triggered interplate thrusting events occurred as part of this sequence. The 1966 doublet ruptured north of the 1980 and 2009 events and also produced widespread aftershock activity. The 2013 earthquake rupture propagated southward from the northern corner of the trench with shallow slip that generated a substantial tsunami. The repeated occurrence of large earthquake doublets along the northern Vanuatu subduction zone is remarkable considering the doublets likely involved overlapping, yet different combinations of asperities. The frequent occurrence of large doublet events and rapid aftershock expansion in this region indicate the presence of small, irregularly spaced asperities along the plate interface.

Magnetocaloric alloy, Gd5Si2Ge2, was developed into a composite with the poly(vinylidene fluoride) (PVDF) piezoelectric polymer. This multifunctional material possesses unique properties that are suitable for energy conversion and harvesting. Experimental approaches include using an arc melting technique to synthesize the Gd5Si2Ge2 (GSG) alloy and the spinning casting method to fabricate the composite. The materials were characterized using various techniques at different length scales. These include atomic force microscopy (AFM), optical microscopy, scanning electron microscopy (SEM) with energy dispersive spectroscopy (EDS), x-ray diffraction (XRD), and x-ray photoelectron spectroscopy (XPS). The results indicated that the phase transformation of the magnetocaloric material close to its Curie temperature induced a significant increase in power generation in the piezoelectric polymer. The power output of a laminated structure was 1.1 mW, more than 200 thousand times higher than the piezoelectric materials alone (5.1 nW).