pinecone/core-2020-05-10-deduplication huggingface dataset:
Multichannel Seismic Imaging of the Rivera Plate Subduction at the Seismogenic Jalisco Block Area (Western Mexican Margin)

Bartolomé, Rafael ... et. al.-- Special issue Geodynamics of the Latin American Pacific Margin.-- 20 pages, 11 figuresDuring the TSUJAL marine geophysical survey, conducted in February and March 2014, Spanish, Mexican and British scientists and technicians explored the western margin of Mexico, considered one of the most active seismic zones in America. This work aims to characterize the internal structure of the subduction zone of the Rivera plate beneath the North American plate in the offshore part of the Jalisco Block, to link the geodynamic and the recent tectonic deformation occurring there with the possible generation of tsunamis and earthquakes. For this purpose, it has been carried out acquisition, processing and geological interpretation of a multichannel seismic reflection profile running perpendicular to the margin. Crustal images show an oceanic domain, dominated by subduction–accretion along the lower slope of the margin with a subparallel sediment thickness of up to 1.6 s two-way travel time (approx. 2 km) in the Middle American Trench. Further, from these data the region appears to be prone to giant earthquake production. The top of the oceanic crust (intraplate reflector) is very well imaged. It is almost continuous along the profile with a gentle dip (<10°); however, it is disrupted by normal faulting resulting from the bending of the plate during subduction. The continental crust presents a well-developed accretionary prism consisting of highly deformed sediments with prominent slumping towards the trench that may be the result of past tsunamis. Also, a bottom simulating reflector (BSR) is identified in the first half a second (twtt) of the section. High amplitude reflections at around 7–8 s twtt clearly image a discontinuous Moho, defining a very gentle dipping subduction planeWe gratefully acknowledge financial support from MINECO (Spain) through TSUJAL project (CGL2011-29474-C02-01) and “Ramon y Cajal” program (R. Bartolome), and from Mexico through CONACYT–FOMIXJAL 2008–96567 (2009); CONACYT–FOMIXJAL 2008–96539 (2009); CONACYT–FOMIXJAL 2010–149245 (2011); CONACyT-FOMIXJal (2012-08-189963) and also partial funding was provided by UNAM DGAPA Grant #IN115513-3Peer Reviewe
Tsunami Bores in Kitakami River

The 2011 Tohoku tsunami entered the Kitakami river and propagated there as a
train of shock waves, recorded with a 1-min interval at water level stations at
Fukuchi, Iino, and the weir 17.2 km from the mouth, where the bulk of the wave
was reflected back. The records showed that each bore kept its shape and
identity as it traveled a 10.9-km-path Fukuchi-Iino-weir-Iino. Shock handling
based on the cross-river integrated classical shock conditions was applied to
reconstruct the flow velocity time histories at the measurement sites, to
estimate inflow into the river at each site, to evaluate the wave heights of
incident and reflected tsunami bores near the weir, and to estimate propagation
speed of the individual bores. Theoretical predictions are verified against the
measurements. We discuss experiences of exercising the shock conditions with
actual tsunami measurements in the Kitakami river, and test applicability of
the shallow-water approximation for describing tsunami bores with heights
ranging from 0.3 m to 4 m in a river segment with a depth of 3-4 m.Comment: 26 pages, 13 figure
Adjoint Methods for Guiding Adaptive Mesh Refinement in Tsunami Modeling

One difficulty in developing numerical methods for tsunami modeling is the
fact that solutions contain regions where much higher resolution is required
than elsewhere in the domain, particularly since the solution may contain
discontinuities or other localized features. The Clawpack software deals with
this issue by using block-structured adaptive mesh refinement to selectively
refine around propagating waves. For problems where only a target area of the
total solution is of interest (e.g. one coastal community), a method that
allows identifying and refining the grid only in regions that influence this
target area would significantly reduce the computational cost of finding a
solution.
  In this work, we show that solving the time-dependent adjoint equation and
using a suitable inner product with the forward solution allows more precise
refinement of the relevant waves. We present examples solving the shallow water
equations in one and two dimensions. To perform these simulations, the use of
the adjoint method has been integrated into the adaptive mesh refinement
strategy of the open source GeoClaw software. We also present results that show
that the accuracy of the solution is maintained and the computational time
required is significantly reduced through the integration of the adjoint method
into adaptive mesh refinement.Comment: Much of this material appeared in a previous pre-print, which can be
  found at arXiv:1511.03645 . Here, the material has been rewritten to focus on
  shallow water equations and submitted to a more application focused journa
Seasonal and Lunar month periods observed in natural neutron flux at
  high altitude

Air radon concentration measurement is useful for research on geophysical
effects, but it is strongly sensitive to site geology and many geophysical and
microclimatic processes such as wind, ventilation, air humidity and so on that
induce very big fluctuations on the concentration of radon in air. On the
contrary, monitoring the radon concentration in soil by measuring the thermal
neutron flux reduces environmental effects. In this paper we report some
experimental results on the natural thermal neutron flux as well as the
concentration of air radon and its variations at 4300 m a.s.l. These results
were obtained with unshielded thermal neutron scintillation detectors
(en-detectors) and radon monitors located inside the ARGO-YBJ experimental
hall. The correlation of these variations with the lunar month and 1-year
period is undoubtedly confirmed. A method for earthquakes prediction provided
by a global net of the en-detectors is currently under study.Comment: 16 pages, 7 figure
Characteristics of viscoelastic crustal deformation following a megathrust earthquake: discrepancy between the apparent and intrinsic relaxation time constants

The viscoelastic deformation of an elastic–viscoelastic composite system is significantly different from that of a simple viscoelastic medium. Here, we show that complicated transient deformation due to viscoelastic stress relaxation after a megathrust earthquake can occur even in a very simple situation, in which an elastic surface layer (lithosphere) is underlain by a viscoelastic substratum (asthenosphere) under gravity. Although the overall decay rate of the system is controlled by the intrinsic relaxation time constant of the asthenosphere, the apparent decay time constant at each observation point is significantly different from place to place and generally much longer than the intrinsic relaxation time constant of the asthenosphere. It is also not rare that the sense of displacement rate is reversed during the viscoelastic relaxation. If we do not bear these points in mind, we may draw false conclusions from observed deformation data. Such complicated transient behavior can be explained mathematically from the characteristics of viscoelastic solution: for an elastic–viscoelastic layered half-space, the viscoelastic solution is expressed as superposition of three decaying components with different relaxation time constants that depend on wavelength
Air-burst Generated Tsunamis

This paper examines the questions of whether smaller asteroids that burst in
the air over water can generate tsunamis that could pose a threat to distant
locations. Such air burst-generated tsunamis are qualitatively different than
the more frequently studied earthquake-generated tsunamis, and differ as well
from impact asteroids. Numerical simulations are presented using the shallow
water equations in several settings, demonstrating very little tsunami threat
from this scenario. A model problem with an explicit solution that demonstrates
and explains the same phenomena found in the computations is analyzed. We
discuss the question of whether compressibility and dispersion are important
effects that should be included, and show results from a more sophisticated
model problem using the linearized Euler equations that begins to addresses
this.Comment: submitte
Influence of Landscape Coverage on Measuring Spatial and Length Properties of Rock Fracture Networks: Insights from Numerical Simulation

Natural fractures are ubiquitous in the Earth’s crust and often deeply buried in the subsurface. Due to the difficulty in accessing to their three-dimensional structures, the study of fracture network geometry is usually achieved by sampling two-dimensional (2D) exposures at the Earth’s surface through outcrop mapping or aerial photograph techniques. However, the measurement results can be considerably affected by the coverage of forests and other plant species over the exposed fracture patterns. We quantitatively study such effects using numerical simulation. We consider the scenario of nominally isotropic natural fracture systems and represent them using 2D discrete fracture network models governed by fractal and length scaling parameters. The groundcover is modelled as random patches superimposing onto the 2D fracture patterns. The effects of localisation and total coverage of landscape patches are further investigated. The fractal dimension and length exponent of the covered fracture networks are measured and compared with those of the original non-covered patterns. The results show that the measured length exponent increases with the reduced localisation and increased coverage of landscape patches, which is more evident for networks dominated by very large fractures (i.e. small underlying length exponent). However, the landscape coverage seems to have a minor impact on the fractal dimension measurement. The research findings of this paper have important implications for field survey and statistical analysis of geological systems
Division by Flat Ultradifferentiable Functions and Sectorial Extensions

We consider classes $ \mathcal{A}_M(S) $ of functions holomorphic in an open
plane sector $ S $ and belonging to a strongly non-quasianalytic class on the
closure of $ S $. In $ \mathcal{A}_M(S) $, we construct functions which are
flat at the vertex of $ S $ with a sharp rate of vanishing. This allows us to
obtain a Borel-Ritt type theorem for $ \mathcal{A}_M(S) $ extending previous
results by Schmets and Valdivia. We also derive a division property for ideals
of flat ultradifferentiable functions, in the spirit of a classical $ C^\infty
$ result of Tougeron.Comment: Slight update of the published version. The definition of closedness
  in subsections 4.1 and 4.2 is less restrictive. One minor typo correcte
Orbit spaces of free involutions on the product of two projective spaces

Let $X$ be a finitistic space having the mod 2 cohomology algebra of the
product of two projective spaces. We study free involutions on $X$ and
determine the possible mod 2 cohomology algebra of orbit space of any free
involution, using the Leray spectral sequence associated to the Borel fibration
$X \hookrightarrow X_{\mathbb{Z}_2} \longrightarrow B_{\mathbb{Z}_2}$. We also
give an application of our result to show that if $X$ has the mod 2 cohomology
algebra of the product of two real projective spaces (respectively complex
projective spaces), then there does not exist any $\mathbb{Z}_2$-equivariant
map from $\mathbb{S}^k \to X$ for $k \geq 2$ (respectively $k \geq 3$), where
$\mathbb{S}^k$ is equipped with the antipodal involution.Comment: 14 pages, to appear in Results in Mathematic
Explicit formulas for the Green's function and the Bergman kernel for monogenic functions in annular shaped domains in Rn+1

By applying a reflection principle we set up fully explicit representation formulas for the harmonic Green's function for orthogonal sectors of the annulus of the unit ball of R-n. From the harmonic Green's function we then can determine the Bergman kernel function of Clifford holomorphic functions by applying an appropriate vector differentiation. As a concrete application we give an explicit analytic representation formula of the solutions to an n-dimensional Dirichlet problem in annular shaped domains that arises in the context of heat conduction
The Relation Between Automorphism Group and Isometry Group of Randers
  Lie Groups

In this paper we consider simply connected Lie groups equipped with left
invariant Randers metrics which arise from left invariant Riemannian metrics
and left invariant vector fields. Then we study the intersection between
automorphism and isometry groups of these spaces. Finally it has shown that for
any left invariant vector field, in a special case, the Lie group admits a left
invariant Randers metric such that this intersection is a maximal compact
subgroup of the group of automorphisms with respect to which the considered
vector field is invariant
Upper bounds on the first eigenvalue for a diffusion operator via
  Bakry-\'{E}mery Ricci curvature II

Let $L=\Delta-\nabla\varphi\cdot\nabla$ be a symmetric diffusion operator
with an invariant measure $d\mu=e^{-\varphi}dx$ on a complete Riemannian
manifold. In this paper we prove Li-Yau gradient estimates for weighted
elliptic equations on the complete manifold with $|\nabla \varphi|\leq\theta$
and $\infty$-dimensional Bakry-\'{E}mery Ricci curvature bounded below by some
negative constant. Based on this, we give an upper bound on the first
eigenvalue of the diffusion operator $L$ on this kind manifold, and thereby
generalize a Cheng's result on the Laplacian case (Math. Z., 143 (1975)
289-297).Comment: Final version. The original proof of Theorem 2.1 using Li-Yau
  gradient estimate method has been moved to the appendix. The new proof is
  simple and direc
On dirichlet type problems of polynomial dirac equations with boundary conditions

Let ${\bf D}_{\bf x}:= \sum_{i=1}^n \frac{\partial }{\partial x_i} e_i$ be the Euclidean Dirac operator in $\R^n$ and let $P(X) = a_m X^m + \ldots + a_1 X +  a_0$ be a polynomial with  real coefficients. Differential equations of the form $P({\bf D}_{\bf x})u({\bf x}) = 0$ are called homogeneous polynomial Dirac equations with real coefficients. In this paper we treat Dirichlet type problems of the a slighly less general form $P({\bf D}_{\bf x}) u({\bf x}) = f({\bf x})$ (where the roots are exclusively real) with prescribed boundary conditions that avoid blow-ups inside of the domain. We set up analytic representation formulas for the solutions in terms of hypercomplex integral operators and give exact formulas for the integral kernels in the particular cases dealing with spherical and concentric annular domains. The Maxwell and the Klein Gordon equation are included as special subcases in this context
Twisted Surfaces with Null Rotation Axis in Minkowski 3-Space

We examine curvature properties of twisted surfaces with null rotation axis in Minkowski 3-space. That is, we study surfaces that arise when a planar curve is subject to two synchronized rotations, possibly at different speeds, one in its supporting plane and one of this supporting plane about an axis in the plane. Moreover, at least one of the two rotation axes is a null axis. As is clear from its construction, a twisted surface generalizes the concept of a surface of revolution. We classify flat, constant Gaussian curvature, minimal and constant mean curvature twisted surfaces with a null rotation axis. Aside from pseudospheres, pseudohyperbolic spaces and cones, we encounter B-scrolls in these classifications. The appearance of B-scrolls in these classifications is of course the result of the rotation about a null axis. As for the cones in the classification of flat twisted surfaces, introducing proper coordinates, we prove that they are determined by so-called Clelia curves. With a Clelia curve we mean a curve that has linear dependent spherical coordinates.status: publishe
Invariant Tensors under the Twin Interchange of Norden Metrics on Almost
  Complex Manifolds

The object of study are almost complex manifolds with a pair of Norden
metrics, mutually associated by means of the almost complex structure. More
precisely, a torsion-free connection and tensors with geometric interpretation
are found which are invariant under the twin interchange, i.e. the swap of the
counterparts of the pair of Norden metrics and the corresponding Levi-Civita
connections. A Lie group depending on four real parameters is considered as an
example of a 4-dimensional manifold of the studied type. The mentioned
invariant objects are found in an explicit form.Comment: 13 page
Liouville property for solutions of the linearized degenerate thin film
  equation of fourth order in a halfspace

We consider a boundary value problem in the half-space for a linear parabolic
equation of fourth order with a degeneration on the boundary of the half-space.
The equation under consideration is substantially a linearized thin film
equation. We prove that, if the right hand side of the equation and the
boundary condition are polynomials in the tangential variables and time, the
same property has any solution of a power growth. It is shown also that the
specified property does not apply to normal variable. As an application, we
present a theorem of uniqueness for the problem in the class of functions of
power growth.Comment: The final version is available on Springer at DOI:
  10.1007/s00025-015-0467-
Semi-inner products and the concept of semi-polarity

The lack of an inner product structure in Banach spaces yields the motivation
to introduce a semi-inner product with a more general axiom system, one missing
the requirement for symmetry, unlike the one determing a Hilbert space. We use
it on a finite dimensional real Banach space $(\X, \| \cdot\|)$ to define and
investigate three concepts. First, we generalize that of \emph{antinorms},
already defined in Minkowski planes, for even dimensional spaces. Second, we
introduce \emph{normality maps}, which in turn leads us to the study of
\emph{semi-polarity}, a variant of the notion of polarity, which makes use of
the underlying semi-inner product.Comment: 16 page
Isomorphism and isotopism classes of filiform Lie algebras of dimension
  up to seven

Since the introduction of the concept of isotopism of algebras by Albert in
1942, a prolific literature on the subject has been developed for distinct
types of algebras. Nevertheless, there barely exists any result on the problem
of distributing Lie algebras into isotopism classes. The current paper is a
first step to deal with such a problem. Specifically, we define a new series of
isotopism invariants and we determine explicitly the distribution into
isotopism classes of $n$-dimensional filiform Lie algebras, for $n\leq 7$. We
also deal with the distribution of such algebras into isomorphism classes, for
which we confirm some known results and we prove that there exist $p+8$
isomorphism classes of seven-dimensional filiform Lie algebras over the finite
field $\mathbb{F}_p$ if $p\neq 2$.Comment: 20 pages, preliminary versio
Envelopes of Legendre Curves in the Unit Tangent Bundle over the Euclidean Plane

For singular plane curves, the classical definitions of envelopes are vague. In order to define envelopes for singular plane curves, we introduce a one-parameter family of Legendre curves in the unit tangent bundle over the Euclidean plane and the curvature. Then we give a definition of an envelope for the one-parameter family of Legendre curves. We investigate properties of the envelopes. For instance, the envelope is also a Legendre curve. Moreover, we consider bi-Legendre curves and give a relationship between envelopes
Associated Nijenhuis Tensors on Manifolds with Almost Hypercomplex
  Structures and Metrics of Hermitian-Norden Type

An associated Nijenhuis tensor of endomorphisms in the tangent bundle is
introduced. Special attention is paid to such tensors for an almost
hypercomplex structure and the metric of Hermitian-Norden type. There are
studied relations between the six associated Nijenhuis tensors as well as their
vanishing. It is given a geometric interpretation of the vanishing of these
tensors as a necessary and sufficient condition for the existence of a unique
connection with totally skew-symmetric torsion tensor. Similar idea is used in
the paper of T. Friedrich and S. Ivanov in Asian J. Math. (2002) for some other
structures. Finally, an example of a 4-dimensional manifold of the considered
type with vanishing associated Nijenhuis tensors is given.Comment: 13 page
Two types of invariant Subspaces in the polydisc

It is known that the structure of invariant subspaces of the Hardy space
$H^2(\mathbb D^n)$ on the polydisc $\mathbb{D}^n$ is very complicated; hence,
we need good examples help us to understand the structure of invariant
subspaces of $H^2(\mathbb D^n)$. In this paper, we define two types of
invariant subspaces of $H^2(\mathbb D^n)$. Then, we give a characterization of
these types invariant subspaces in view of the Beurling-Lax-Halmos Theorem.
Unitary equivalence is also studied in this paper.Comment: 8 pages, this is a preliminary version of the paper and all
  comments/suggestions are welcom
4-colored graphs and knot/link complements

A representation for compact 3-manifolds with non-empty non-spherical
boundary via 4-colored graphs (i.e., 4-regular graphs endowed with a proper
edge-coloration with four colors) has been recently introduced by two of the
authors, and an initial classification of such manifolds has been obtained up
to 8 vertices of the representing graphs. Computer experiments show that the
number of graphs/manifolds grows very quickly as the number of vertices
increases. As a consequence, we have focused on the case of orientable
3-manifolds with toric boundary, which contains the important case of
complements of knots and links in the 3-sphere. In this paper we obtain the
complete catalogation/classification of these 3-manifolds up to 12 vertices of
the associated graphs, showing the diagrams of the involved knots and links.
For the particular case of complements of knots, the research has been extended
up to 16 vertices.Comment: 19 pages, 6 figures, 3 tables; changes in Lemma 6, Corollaries 7 and
On Positive-Characteristic Semi-Parametric Local-Uniform Reductions of
  Varieties over Finitely Generated $\mathbb{Q}$-Algebras

We present a non-standard proof of the fact that the existence of a local
(i.e. restricted to a point) characteristic-zero, semi-parametric lifting for a
variety defined by the zero locus of polynomial equations over the integers is
equivalent to the existence of a collection of local semi-parametric
(positive-characteristic) reductions of such variety for almost all primes
(i.e. outside a finite set), and such that there exists a global complexity
bounding all the corresponding structures involved. Results of this kind are a
fundamental tool for transferring theorems in commutative algebra from a
characteristic-zero setting to a positive-characteristic one
A note on completeness of weighted normed spaces of analytic functions

Given a non-negative weight $v$, not necessarily bounded or strictly
positive, defined on a domain $G$ in the complex plane, we consider the
weighted space $H_v^\infty(G)$ of all holomorphic functions on $G$ such that
the product $v|f|$ is bounded in $G$ and study the question of when is such a
space complete under the canonical sup-seminorm. We obtain both some necessary
and some sufficient conditions in terms of the weight $v$, exhibit several
relevant examples, and characterize completeness in the case of spaces with
radial weights on balanced domains.Comment: 20 pages. The title of the first version was confusing and was
  changed accordingly in the second version. In the third version several
  misprints have been corrected and some explanations have been clarified and
  in the fourth version a few minor misprints were correcte