1,280 research outputs found
Receipt, Property tax, 25 January 1859
https://egrove.olemiss.edu/aldrichcorr_c/1185/thumbnail.jp
Schmidt hammer and terrestrial laser scanning (TLS) used to detect single‐event displacements on the Pleasant Valley fault (Nevada, USA)
Changes in surface roughness on carbonate fault scarps often reflect varying durations of subaerial weathering. On the Pleasant Valley fault in central Nevada, the documentation of a surface rupture in 1915, a long recurrence interval of faulting, slow weathering rate, and a relatively high (2–3 m) single‐event displacement make the discrimination of the historical and penultimate slip patches unambiguous. Following from a 2018 study, we used a Schmidt hammer and terrestrial laser scanning (TLS) to further test whether these weathering patterns delineate exposed slip patches on a fault scarp. Results show that Schmidt hammer rebound value ranges (termed ΔR – the difference between minimum and maximum R‐values in repeat impacts at a point), increase by ~8–10 points across the historical–penultimate event transition zone in two separate scarp transects. TLS‐derived surface roughness also indicates a clear difference between the most recent and penultimate events. The average single‐event displacement (SED) estimated using the Schmidt hammer and TLS is 2.85 m at two transect sites and is roughly equivalent to the visually estimated 3 m. While this fault is an ideal case where we know some of the slip history, the results demonstrate that these techniques show promise for discriminating slip patches on larger carbonate fault scarps with longer paleoearthquake histories, and could be used alongside 36Cl cosmogenic exposure‐age dating to improve paleoseismic records on normal faults. © 2019 John Wiley & Sons, Ltd.The Schmidt hammer and terrestrial laser scanning (TLS) can detect hardness and mm‐ to cm‐scale surface roughness changes on bedrock fault scarps. Here, we demonstrate that these changes occur between the ‘slip patches’ of a 1915 and pre‐1915 event on the Pleasant Valley fault, yielding single event displacements of ~2‐3 m. These techniques can now be combined to estimate SEDs on larger fault scarps with longer records of paleoearthquakes.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/154454/1/esp4748.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/154454/2/esp4748_am.pd
On Exchange of Orbital Angular Momentum Between Twisted Photons and Atomic Electrons
We obtain an expression for the matrix element for a twisted
(Laguerre-Gaussian profile) photon scattering from a hydrogen atom. We consider
photons incoming with an orbital angular momentum (OAM) of ,
carried by a factor of not present in a plane-wave or pure
Gaussian profile beam. The nature of the transfer of units of OAM from
the photon to the azimuthal atomic quantum number of the atom is investigated.
We obtain simple formulae for these OAM flip transitions for elastic forward
scattering of twisted photons when the photon wavelength is large
compared with the atomic target size , and small compared the Rayleigh range
, which characterizes the collimation length of the twisted photon beam.Comment: 16 page
RJaCGH: Bayesian analysis of aCGH arrays for detecting copy number changes and recurrent regions
Summary: Several methods have been proposed to detect copy number changes and recurrent regions of copy number variation from aCGH, but few methods return probabilities of alteration explicitly, which are the direct answer to the question ‘is this probe/region altered?’ RJaCGH fits a Non-Homogeneous Hidden Markov model to the aCGH data using Markov Chain Monte Carlo with Reversible Jump, and returns the probability that each probe is gained or lost. Using these probabilites, recurrent regions (over sets of individuals) of copy number alteration can be found
Post-Prior discrepancies in CDW-EIS calculations for ion impact ionization fully differential cross sections
In this work we present fully differential cross sections (FDCSs)
calculations using post and prior version of CDW--EIS theory for helium single
ionization by 100 MeV C amu and 3.6 MeV amu Au and
Au ions. We performed our calculations for different momentum transfer
and ejected electron energies. The influence of internuclear potential on the
ejected electron spectra is taken into account in all cases. We compare our
calculations with absolute experimental measurements. It is shown that prior
version calculations give better agreement with experiments in almost all
studied cases.Comment: 9 pages, 7 figure
The climate sensitivity of Norway spruce [Picea abies (L.) Karst.] in the southeastern European Alps
Tree ring chronologies were developed from trees growing at two sites in Slovenia which differed in their ecological and climatological characteristics. Ring width, maximum latewood density, annual height increment and latewood cellulose carbon isotope composition were developed at both sites and time-series verified against instrumental climate data over the period (AD 1960–AD 2002). Ring width sensitivity to summer temperature is site-dependent, with contrasting responses at alpine and lowland sites. Maximum density responds to September temperatures, suggesting lignification after cell division has ended for the season. Stable carbon isotopes have great potential, responding to summer temperature at oth alpine and lowland stands. Height increment appears relatively insensitive to climate, and is likely to be dominated by local stand dynamics
High potential for weathering and climate effects of non-vascular vegetation in the Late Ordovician
It has been hypothesized that predecessors of today’s bryophytes significantly increased global chemical weathering in the Late Ordovician, thus reducing atmospheric CO2 concentration and contributing to climate cooling and an interval of glaciations. Studies that try to quantify the enhancement of weathering by non-vascular vegetation, however, are usually limited to small areas and low numbers of species, which hampers extrapolating to the global scale and to past climatic conditions. Here we present a spatially explicit modelling approach to simulate global weathering by non-vascular vegetation in the Late Ordovician. We estimate a potential global weathering flux of 2.8 (km3 rock) yr−1, defined here as volume of primary minerals affected by chemical transformation. This is around three times larger than today’s global chemical weathering flux. Moreover, we find that simulated weathering is highly sensitive to atmospheric CO2 concentration. This implies a strong negative feedback between weathering by non-vascular vegetation and Ordovician climate
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