The planning process for California's Marine Life Protection Act in north central California represents a case study in the design of a regional component of a statewide network of marine protected areas (MPAs) for improved ecosystem protection. We describe enabling factors, such as a legislative mandate, political will, and adequate capacity and funding that fostered a successful planning process. We identify strategic principles that guided the design of a transparent public planning process that delivered regional MPA network proposals, which both met science guidelines and achieved a high level of support among stakeholders. We also describe key decision support elements (spatial data, planning tools, and scientific evaluation) that were essential for designing, evaluating, and refining alternative MPA network proposals and for informing decision-makers. 相似文献
Traditionally, earthquake impact assessments have been made via fieldwork by non-governmental organisations (NGO's) sponsored data collection; however, this approach is time-consuming, expensive and often limited. Recently, social media (SM) has become a valuable tool for quickly collecting large amounts of first-hand data after a disaster and shows great potential for decision-making. Nevertheless, extracting meaningful information from SM is an ongoing area of research. This paper tests the accuracy of the pre-trained sentiment analysis (SA) model developed by the no-code machine learning platform MonkeyLearn using the text data related to the emergency response and early recovery phase of the three major earthquakes that struck Albania on the 26th November 2019. These events caused 51 deaths, 3000 injuries and extensive damage. We obtained 695 tweets with the hashtags: #Albania #AlbanianEarthquake, and #albanianearthquake from the 26th November 2019 to the 3rd February 2020. We used these data to test the accuracy of the pre-trained SA classification model developed by MonkeyLearn to identify polarity in text data. This test explores the feasibility to automate the classification process to extract meaningful information from text data from SM in real-time in the future. We tested the no-code machine learning platform's performance using a confusion matrix. We obtained an overall accuracy (ACC) of 63% and a misclassification rate of 37%. We conclude that the ACC of the unsupervised classification is sufficient for a preliminary assessment, but further research is needed to determine if the accuracy is improved by customising the training model of the machine learning platform.
We used climatological composite analysis to investigate El Ni?o-Southern Oscillation (ENSO) signals in long-term shallow ground water level observations from four wells in the lower Fraser Valley of British Columbia. Significance of differences between warm-phase, cold-phase, and neutral climate states was assessed with a Monte Carlo bootstrap technique. We also considered time series of local precipitation and streamflow for comparison. Composite annual hyetographs suggest that ENSO precipitation impacts are largely limited to winter and spring, with higher and lower rainfall occurring, respectively, under cold-phase and warm-phase episodes. This is consistent with prior work in the region and is found to be directly reflected in both streamflow and ground water level data. The mean magnitude of ENSO terrestrial hydrologic anomalies can be up to approximately 50% of the average seasonal cycle amplitude. ENSO does not appear to systematically affect annual hydrometeorological cycle timing in this study area. However, relative to the surface hydrologic systems considered, aquifers are observed to retain a stronger memory of seasonal ENSO-related precipitation anomalies, with changes potentially extending through the following summer, presumably reflecting storage effects. Most responses appear to be somewhat nonlinear. 相似文献
We examine the electromagnetic coupling of a GPS antenna–monument pair in terms of its simulated affect on long GPS coordinate
time series. We focus on the Earth and Polar Observing System (POLENET) monument design widely deployed in Antarctica and
Greenland in projects interested particularly in vertical velocities. We base our tests on an absolute robot calibration that
included the top ~0.15 m of the monument and use simulations to assess its effect on site coordinate time series at eight
representative POLENET sites in Antarctica over the period 2000.0–2011.0. We show that the neglect of this calibration would
introduce mean coordinate bias, and most importantly for velocity estimation, coordinate noise which is highly sensitive to
observation geometry and hence site location and observation period. Considering only sub-periods longer than 2.5 years, we
show vertical site velocities may be biased by up to ±0.4 mm/year, and biases up to 0.2 mm/year may persist for observation
spans of 8 years. Changing between uniform and elevation-dependent observation weighting alters the time series but does not
remove the velocity biases, nor does ambiguity fixing. The effect on the horizontal coordinates is negligible. The ambiguities
fixed series spectra show noise between flicker and random walk with near-white noise at the highest frequencies, with mean
spectral indices (frequencies <20 cycles per year) of approximately −1.3 (uniform weighting) and −1.4 (elevation-dependent
weighting). While the results are likely highly monument specific, they highlight the importance of accounting for monument
effects when analysing vertical coordinate time series and velocities for the highest precision and accuracy geophysical studies. 相似文献
The forthcoming GRAV-D gravimetric geoid model over the United States is to be updated regularly to account for changes in
geoid height. Its baseline precision is to be at the 10–20 mm level over non-mountainous regions. The aim of this study is
to provide an estimate of the magnitude, time scale, and spatial footprint of geoid height change over North America, from
mass redistribution processes of hydrologic, cryospheric and solid Earth nature. Geoid height changes from continental water
storage changes over the past 50 years and predicted over the next century are evaluated and are highly dependent on the used
model. Groundwater depletion from anthropogenic pumping in regional scale aquifers may lead to geoid changes of 10 mm magnitude
every 50–100 years. The GRACE time varying gravity fields are used to (i) assess the errors in a glacial isostatic adjustment
model, which, if used to correct the GRAV-D model, may induce errors at the 10 mm geoid height level after ~20 years, (ii),
evaluate geoid height change over ice mass loss regions of North America, which, if they remain unchanged in the future, may
lead to geoid height changes at the 10 mm level in under a decade and (iii), compute sea level rise and its effect on the
geoid, which is found to be negligible. Coseismic gravitational changes from past North American earthquakes are evaluated,
and lead to geoid change at the 10-mm level for only the largest thrust earthquakes. Finally, geoid change from volcanic processes
are assessed and found to be significant with respect to the GRAV-D geoid model baseline precision for cataclysmic events,
such as that of the 1980 Mt. St. Helens eruption. Recommendations on how to best monitor geoid change in the future are given. 相似文献
We present a multiproxy paleoclimate record using leaf wax hydrogen isotopes (??2Hwax) and varve thickness from Arctic proglacial lake sediments. We also provide one of the first evaluations of the utility of ??2Hwax as a paleoclimate proxy in Arctic proglacial lakes. We compare varve thickness and ??2Hwax at sub-decadal resolution from 1948 to 2004 AD, and at sub-centennial resolution from 1450 to 2004 AD. Varve thickness and ??2Hwax both contain large interannual variability and are anti-correlated during the late twentieth century, suggesting that both proxies respond rapidly, but by different mechanisms, to catchment-scale forcings. At longer time scales, varve thickness exhibits a strong response to Little Ice Age cooling (1661?C1827 AD in this record) but does not show evidence for twentieth century warming recorded throughout the Arctic. ??2Hwax does record regional-scale temperature changes, with more 2H-depleted values during the Little Ice Age and an abrupt change to more 2H-enriched values in the twentieth century. This corresponds well with a recent Arctic-wide temperature reconstruction in which the seventeenth century is the coldest interval, and the twentieth century is the warmest interval. Our results suggest that ??2Hwax is a promising proxy that can be applied at high resolution in proglacial Arctic lakes. 相似文献
Iron emission lines at 6.4–6.97 keV, identified with fluorescent Kα transitions, are among the strongest discrete features in the X-ray band. These are therefore one of the most powerful probes to infer the properties of the plasma in the innermost part of the accretion disc around a compact object. In this paper, we present a recent XMM–Newton observation of the X-ray burster 4U 1705−44, where we clearly detect a relativistically smeared iron line at about 6.7 keV, testifying with high statistical significance that the line profile is distorted by high-velocity motion in the accretion disc. As expected from disc reflection models, we also find a significant absorption edge at about 8.3 keV; this feature appears to be smeared, and is compatible with being produced in the same region where the iron line is produced. From the line profile, we derive the physical parameters of the inner accretion disc with large precision. The line is identified with the Kα transition of highly ionized iron, Fe xxv , the inner disc radius is R in= 14 ± 2 R g (where R g is the Gravitational radius, GM / c 2 ), the emissivity dependence from the disc radius is r −2.27±0.08 , the inclination angle with respect to the line of sight is i = 39°± 1° . Finally, the XMM–Newton spectrum shows evidences of other low-energy emission lines, which again appear broad and their profiles are compatible with being produced in the same region where the iron line is produced. 相似文献
Precisely how Upper Palaeolithic human ecology was shaped by changing climate during the Pleniglacial remains a matter of debate, for while this generally cold period is now understood to include complex and often rapid flux in climate, there are still considerable difficulties in resolving climatic variations at particular times and places — derived from various lines of proxy evidence — with the high-resolution proxy record of temperature changes from oxygen isotope analysis of the Greenland ice-cores.In this paper we apply the methodology of large-scale flotation to newly excavated contexts from the Upper Palaeolithic (Gravettian) site of Dolní V?stonice II, Czech Republic, to explore the potential of charcoal — as a natural archive of environmental information — to offer information on environmental change towards the end of the middle pleniglacial during Oxygen Isotope Stage 3, between c. 32,500 and 31,200 Cal yr BP. The results of an analysis of ring widths and other anatomical features — interpreted alongside micromorphological data — indicate that this charcoal may capture a higher-resolution record of the changing climatic conditions during which humans were first expanding into these hitherto marginal ecologies and, consequently, shed new light upon the complexity of the lifeways that enabled them to do so. 相似文献