bluuebunny/crossref_metadata_2025_split huggingface dataset:
Global observation of vertical‐CLVD earthquakes at active volcanoes
Authors: Shuler Ashley , Nettles Meredith , Ekström Göran 
Published: December 2012

AbstractSome of the largest and most anomalous volcanic earthquakes have non‐double‐couple focal mechanisms. Here, we investigate the link between volcanic unrest and the occurrence of non‐double‐couple earthquakes with dominant vertical tension or pressure axes, known as vertical compensated‐linear‐vector‐dipole (vertical‐CLVD) earthquakes. We determine focal mechanisms for 313 target earthquakes from the standard and surface wave catalogs of the Global Centroid Moment Tensor Project and identify 86 shallow 4.3 ≤ MW ≤ 5.8 vertical‐CLVD earthquakes located near volcanoes that have erupted in the last ~100 years. The majority of vertical‐CLVD earthquakes occur in subduction zones in association with basaltic‐to‐andesitic stratovolcanoes or submarine volcanoes, although vertical‐CLVD earthquakes are also located in continental rifts and in regions of hot spot volcanism. Vertical‐CLVD earthquakes are associated with many types of confirmed or suspected eruptive activity at nearby volcanoes, including volcanic earthquake swarms as well as effusive and explosive eruptions and caldera collapse. Approximately 70% of all vertical‐CLVD earthquakes studied occur during episodes of documented volcanic unrest at a nearby volcano. Given that volcanic unrest is underreported, most shallow vertical‐CLVD earthquakes near active volcanoes are likely related to magma migration or eruption processes. Vertical‐CLVD earthquakes with dominant vertical pressure axes generally occur after volcanic eruptions, whereas vertical‐CLVD earthquakes with dominant vertical tension axes generally occur before the start of volcanic unrest. The occurrence of these events may be useful for identifying volcanoes that have recently erupted and those that are likely to erupt in the future.
Displacement characteristics of coarse fluvial bed sediment
Authors: Hassan Marwan A. , Voepel Hal , Schumer Rina , Parker Gary , Fraccarollo Luigi 
Published: December 2012

AbstractPrevious work highlights the need for data collection to identify appropriate models for temporal evolution of tracer dispersal in rivers. Results of 64 gravel‐bed field tracer experiments covering a wide range of flow and sediment supply regimes are compiled here to determine the probabilistic character of gravel transport. We focus on whether particle travel distances and waits are thin‐ or heavy‐tailed. While heavy‐tailed travel distance distributions are observed between successive monitoring events in different hydrological and sediment supply regimes, heavy‐tailedness does not persist through total travel distance over multiple monitoring events, suggesting that individual monitoring events occur before particle travel distance exceeds the characteristic correlation length for the channel (such that particles that start in fast paths remain in fast paths and particles in slow paths remain in slow paths). After a large number of transport events, super‐diffusive spreading was not observed at any of the gravel bed streams. Continuous‐time tracking of x, y, z coordinates of tracers in natural streams is necessary to capture exact step and waiting time distributions.
Soil organic carbon mobilization by interrill erosion: Insights from size fractions
Authors: Wang Zhengang , Govers Gerard , Oost Kristof Van , Clymans Wim , den Putte An Van , Merckx Roel 
Published: December 2012

AbstractSediments mobilized by interrill erosion are often highly enriched in soil organic carbon (SOC) in comparison to source soils. This selectivity may lead to the preferential mobilization of SOC with specific properties, e.g., SOC that is especially susceptible to decomposition. This may then have important implications with respect to the role of soil erosion in the global carbon cycle. We addressed this issue by investigating the behavior of different SOC components in field rainfall simulation experiments on arable fields in loess‐derived soils. We characterized the mobilization of mineral‐bound organic carbon (MOC) and particulate organic carbon (POC) by interrill erosion using size fractionation and we used the C:N ratio as a tracer variable to determine the composition of the SOC in eroded sediments. MOC was found to be preferentially mobilized by interrill erosion in comparison to POC. The enrichment ratio (i.e., the ratio of the concentration of a soil constituent in the eroded sediment to its concentration in the original soil) of MOC decreased with increasing sediment concentration. The enrichment ratio of POC displayed a similar pattern to that of MOC but enrichment was less pronounced. Furthermore, sediments were found to be enriched in fine POC while they were impoverished with respect to coarse POC. The selective MOC mobilization together with the dominance of MOC in the total SOC pool in the soil explained the dominance of MOC in interrill eroded sediment. The fact that it is mainly MOC that is mobilized by interrill erosion implies that the SOC in the interrill eroded sediments is on average at least as recalcitrant than that in the source soils which may have important implications for the fate of the mobilized SOC. In order to understand the role of soil erosion in C cycling, MOC and POC need to be considered separately not only because they are chemically different but also because of their different behaviors with respect to geomorphic processes.
Recurring dynamically induced thinning during 1985 to 2010 on Upernavik Isstrøm, West Greenland
Authors: Khan Shfaqat Abbas , Kjær Kurt H. , Korsgaard Niels J. , Wahr John , Joughin Ian R. , Timm Lars H. , Bamber Jonathan L. , van den Broeke Michiel R. , Stearns Leigh A. , Hamilton Gordon S. , Csatho Bea M. , Nielsen Karina , Hurkmans Ruud , Babonis Greg 
Published: December 2012

AbstractMany glaciers along the southeast and northwest coasts of Greenland have accelerated, increasing the ice sheet's contribution to global sea‐level rise. In this article, we map elevation changes on Upernavik Isstrøm (UI), West Greenland, during 2003to 2009 using high‐resolution ice, cloud and land elevation satellite laser altimeter data supplemented with altimeter surveys from NASA's Airborne Topographic Mapper during 2002 to 2010. To assess thinning prior to 2002, we analyze aerial photographs from 1985. We document at least two distinct periods of dynamically induced ice loss during 1985 to 2010 characterized by a rapid retreat of the calving front, increased ice speed, and lowering of the ice surface. The first period occurred before 1991, whereas the latter occurred during 2005 to 2009. Analyses of air and sea‐surface temperature suggest a combination of relatively warm air and ocean water as a potential trigger for the dynamically induced ice loss. We estimate a total catchment‐wide ice‐mass loss of UI caused by the two events of 72.3 ± 15.8 Gt during 1985 to 2010, whereas the total melt‐induced ice‐mass loss during this same period is 19.8 ± 2.8 Gt. Thus, 79% of the total ice‐mass loss of the UI catchment was caused by ice dynamics, indicating the importance of including dynamically induced ice loss in the total mass change budget of the Greenland ice sheet.
Geodolite measurements of deformation near Hollister, California, 1971–1978
Authors: Savage J. C. , Prescott W. H. , Lisowski M. , King N. 
Published: December 2012

A 24‐station trilateration network spanning the San Andreas and Calaveras faults near Hollister, California, has been surveyed each year between 1971 and 1978, inclusive. Two moderate (ML = 5) earthquakes have occurred within the network during the interval. No convincing preseismic or coseismic anomalies associated with those earthquakes have been identified. The deformation of the network can be described roughly by rigid body motion of the three blocks bounded by the two faults with accommodation occurring by right‐lateral strike slip on the San Andreas (13±2 mm/a) and Calaveras (17±2 mm/a) faults. The required slip rates are within the range of the observed fault creep on those faults. A more detailed analysis of the deformation indicates appreciable strain accumulation (0.4 μstrain/a tensor shear) within the block lying between the San Andreas and Calaveras faults. Many of the features of the observed deformation can be produced by an elementary dislocation model, indicating that most of the deformation is associated directly with slip on the major faults. The network is not extensive enough to define uniquely the relative motion across the San Andreas fault system, but the data are consistent with a value of about 38 mm/a. The rate of deformation in 1971–1978 was not uniform but rather appears to have been higher than normal in 1973–1974 and lower than normal in 1975–1976.Supplement is available with entire article on microfiche. Order from American Geophysical Union', 2000 Florida Avenue, N.W., Washington, D.C. 20006. Document J79‐008;$01.00. Payment must accompany order.
American URSI broadcasts of cosmic data, January to March, 1939, with American magnetic character‐figure CA, February to April, 1939
Authors: Johnston H. F. 
Published: December 2012

The data for terrestrial magnetism, sunspots, and solar constant are the same as given in previous tables.The first three columns of Table 1 give (1) the magnetic character according to the scale 0‐2 of the International Commission of Terrestrial Magnetism and Atmospheric Electricity, (2) the type featuring the day other than normal by the letters b, p, o, and i for days marked by day, rapid pulsations, long‐period oscillations, and iregular oscillations, respectively, and (3) the hour and minute of Greenwich mean time marking the beginning of a storm, the end of the storm being indicated in the foot‐note to the Table.
Apia Observatory January to March, 1945
Authors: Sapsford H. Bruce 
Published: December 2012

(Latitude 13° 48′.4 S., longitude 171° 46′.5 or 11h 27m.1 W. of Gr.)January 28–29—A moderate storm commenced in H at 14h 55m GMT, January 28, continuing with moderate fluctuations to a maximum at 22h 55m and a minimum at 04h 11m, January 29, and then gradually returned to normal. Only slight fluctuations were observed in D and Z. Range: H, 169 gammas.
Compact high-speed reciprocating probe system for measurements in a Hall thruster discharge and plume
Authors: Dannenmayer K. , Mazouffre S. 
Published: December 2012

A compact high-speed reciprocating probe system has been developed in order to perform measurements of the plasma parameters by means of electrostatic probes in the discharge and the plume of a Hall thruster. The system is based on a piezoelectric linear drive that can achieve a speed of up to 350 mm/s over a travel range of 90 mm. Due to the high velocity of the linear drive the probe can be rapidly moved in and out the measurement region in order to minimize perturbation of the thruster discharge due to sputtering of probe material. To demonstrate the impact of the new system, a heated emissive probe, installed on the high-speed translation stage, was used to measure the plasma potential and the electron temperature in the near-field plume of a low power Hall thruster.
Terrestrial slug problems: classical biological control and beyond.
Authors: Howlett S. A. 
Published: December 2012

Abstract
Slugs are an important crop and ornamental plant pest throughout temperate regions in all sectors of the growing industry. Their pest status is set to increase as environmental considerations such as using reduced tillage and over-winter green crops, along with legislative changes to pesticide usage and more extreme weather patterns favour population growth. Consequently, the need for sustainable approaches to slug control will become ever-more important. This review focuses on biocontrol strategies, including nematodes, sciomyzid flies and microbes. First, an overview of the problems caused by slugs in agriculture and horticulture is given, highlighting the key pest species of temperate climates. This is followed by a brief description of the existing approaches to their control and the current position with regard to classical biological control of slugs is discussed in detail. Finally, future research needs are summarized, along with the challenges involved.
High-value horticulture in developing countries: barriers and opportunities.
Authors: Hewett E. W. 
Published: December 2012

Abstract
High-value horticultural crops, including fruits, vegetables, flowers, aromatic plants and herbs, are key components of agricultural development and economic progress in developing countries. Tropical and subtropical fruit trees are normally grown in these areas, especially when they have a competitive advantage of being harvested when appropriate market windows occur. Intensive production systems, often involving intercropping of fruit trees and vegetables along with a staple grain crop such as maize, provide local population with a balanced, diverse, nutrient-rich diet, an increased income, improved health and well-being through reduction in poverty and malnutrition. This review focuses on three case studies in three continents, each of which has achieved remarkable success in a relatively short time: East Cape, South Africa; Chiapas State, Mexico; and the Sao Francisco River Valley, Northeast Brazil. Significant economic benefits accrued to smallholders, as well as locally and nationally in both Brazil and Mexico, while in South Africa final economic assessments have not been made, although smallholder farmers are receiving incomes that have not existed previously. Key elements in success of these projects included substantial initial funding from a Government or international source that enabled infrastructural development such as creation of irrigation systems in Brazil, selection and supply of quality planting material (propagated trees, plants, vegetable and flower seeds), provision of R&D expertise as well as extension specialists providing education and training. In addition, involvement of local farmers and communities, development of local farmer associations and 'champions' to provide leadership, addition of people with expertise in social, economic, technological, welfare and heritage knowledge is important for ongoing village progress and development. Major challenges exist in creation of a functional and efficient supply chain for postharvest handling, storage and transport, as well as creating stable and profitable market linkages for high-value horticultural products. The common elements in these projects have the potential to be transposed to other developing countries where they have the potential to serve as models for economic and social development.
Anticipating impacts of climate change on organic agriculture.
Authors: Jaradat A. A. 
Published: December 2012

Abstract
Both conventional agriculture (CA) and organic agriculture (OA) are inextricably linked to climate and will impact and be impacted by climate change (CC). OA, unlike CA, encompasses heterogeneous agricultural management methods and practices, given its multiple origins around the world. Although it represents <1% of the world's agricultural production and about 9% of total agricultural area, OA is a globally growing, low-input, dynamic and knowledge-intensive production system. It provides a larger flow of multiple ecosystems services than, and differs fundamentally from, CA in the conceptual approaches that frame crop, animal and natural resources-management strategies. Organic farmers have fewer means to manage their production systems and they need greater expertise and more time to optimize the management of OA in the face of CC. The diverse OA-based agroecological systems (AESs), compared with CA, provide more regulatory functions that enable OA to adjust to changing environmental conditions; however, OA may experience larger inter-annual variability which is attributed to fewer short-term possibilities for controlling biotic and abiotic stresses. Nevertheless, small-scale organic farmers and communities are seemingly able to cope with weather fluctuations and climate extremes because of the self-regulating ability of OA and the enormous variability in internal adaptation strategies they have developed over time. However, vulnerability of OA to CC will eventually depend on the level of exposure and sensitivity to multiple biotic and abiotic stresses, and on its intrinsic buffering capacity for adaptation and mitigation. Long-term sustainability of OA in the face of CC is intractably linked to ecological sustainability. CC and ecological disturbances may force OA to undergo structural changes or adjustments as to land area; farm size and land tenure; farming complexity, crop-livestock integration, sustainable intensification and specialization; environmental stewardship; and labour intensity. Conventionalization, to the extent that it does not undermine its core principles, may become the only economically viable structural change option to adapt large-scale OA to CC. In order to minimize the impact of CC, OA needs to function within the broader context of multidisciplinary agro-ecological principles, while adopting scientifically based, resource-efficient and semi-closed AESs' approach. The challenge facing OA is to develop measurable and reliable biophysical vulnerability indicators to prioritize adaptation and mitigation efforts at the farm and local levels.
Surface code quantum computing by lattice surgery
Authors: Horsman Dominic , Fowler Austin G , Devitt Simon , Meter Rodney Van 
Published: December 2012

Abstract
In recent years, surface codes have become a leading method for quantum error correction in theoretical large-scale computational and communications architecture designs. Their comparatively high fault-tolerant thresholds and their natural two-dimensional nearest-neighbour (2DNN) structure make them an obvious choice for large scale designs in experimentally realistic systems. While fundamentally based on the toric code of Kitaev, there are many variants, two of which are the planar- and defect-based codes. Planar codes require fewer qubits to implement (for the same strength of error correction), but are restricted to encoding a single qubit of information. Interactions between encoded qubits are achieved via transversal operations, thus destroying the inherent 2DNN nature of the code. In this paper we introduce a new technique enabling the coupling of two planar codes without transversal operations, maintaining the 2DNN of the encoded computer. Our lattice surgery technique comprises splitting and merging planar code surfaces, and enables us to perform universal quantum computation (including magic state injection) while removing the need for braided logic in a strictly 2DNN design, and hence reduces the overall qubit resources for logic operations. Those resources are further reduced by the use of a rotated lattice for the planar encoding. We show how lattice surgery allows us to distribute encoded GHZ states in a more direct (and overhead friendly) manner, and how a demonstration of an encoded CNOT between two distance-3 logical states is possible with 53 physical qubits, half of that required in any other known construction in 2D.
Interferometric redatuming by sparse inversion
Authors: van der Neut Joost , Herrmann Felix J. 
Published: December 2012

Abstract
Assuming that transmission responses are known between the surface and a particular depth level in the subsurface, seismic sources can be effectively mapped to this level by a process called interferometric redatuming. After redatuming, the obtained wavefields can be used for imaging below this particular depth level. Interferometric redatuming consists of two steps, namely (i) the decomposition of the observed wavefields into downgoing and upgoing constituents and (ii) a multidimensional deconvolution of the upgoing constituents with the downgoing constituents. While this method works in theory, sensitivity to noise and artefacts due to incomplete acquisition require a different formulation. In this letter, we demonstrate the benefits of formulating the two steps that undergird interferometric redatuming in terms of a transform-domain sparsity-promoting program. By exploiting compressibility of seismic wavefields in the curvelet domain, the method not only becomes robust with respect to noise but we are also able to remove certain artefacts while preserving the frequency content. Although we observe improvements when we promote sparsity in the redatumed data space, we expect better results when interferometric redatuming would be combined or integrated with least-squares migration with sparsity promotion in the image space.
Resolution tests revisited: the power of random numbers
Authors: Trampert Jeannot , Fichtner Andreas , Ritsema Jeroen 
Published: December 2012

Abstract
We propose a simple method where the inversion of synthetic data, corresponding to a zero-mean random input vector, is used to infer the average horizontal and vertical resolution lengths of tomographic models. The method works well if the resolution operator has a diagonally dominant structure. This assumption, although often verified in seismic tomography, can be tested by simply cross-correlating the input with the output of the synthetic simulation. The method is as efficient as a single checkerboard test, but reveals more easily interpretable information.
The Publication and Reception of David Cranz's 1767 History of Greenland
Authors: Jensz Felicity 
Published: December 2012

Abstract
Between the eighteenth and nineteenth centuries, religious books proportionally lost popularity while travel books became more popular. This paper examines a hybrid of these two genres, Protestant missionary monographs, through a detailed analysis of David Cranz's 1767 History of Greenland, including the rationale behind publishing the book; its translation from German into English; how it was used as a political tool to influence British foreign policy; and how the book was received by British literary critics and scientists. This analysis demonstrates how authorial intentions that the religious and secular components of Protestant Missionary literature be considered as parts of a whole produced confusion and tension in the secular reception of such books.
Twin-peak quasi-periodic oscillations and the kinematics of orbital motion in a curved space–time
Authors: Germanà Claudio 
Published: December 2012

Abstract
Twin-peak high-frequency quasi-periodic oscillations (HF QPOs) observed in the power spectra of low-mass X-ray binaries, with either a black hole or a neutron star, have central frequencies that are typical of the orbital motion time-scale close to the compact object. Thus, twin HF QPOs might carry the fingerprint of physical effects in a strongly curved space–time. We study the azimuth phase ϕ(t) for orbital motion in the Schwarzschild metric and calculate the power spectra to check whether they display the features seen in the observed ones. We show that the timing of ϕ(t) on non-closed orbits can account for the observed twin-peak HF QPOs. The uppermost couple of peaks in frequency has the lower peak that corresponds to the azimuthal frequency νϕ, the upper one to νϕ+νr.
The azimuth phase temporal behaviour ϕ(t) on a slightly eccentric orbit in the Schwarzschild metric is described by a linear function of slope νϕ plus an oscillating term at the relativistic radial frequency νr. We deduce that the twin-peak HF QPOs might originate from a frequency modulated signal driven by the kinematics of orbital motion in a curved space–time.