A high resolution stratigraphic framework for the remarkable fossil cetacean assemblage of the Miocene/Pliocene Pisco Formation,Peru

The Miocene/Pliocene Pisco Formation of Peru contains a rich marine vertebrate fossil record, providing a unique opportunity for the study of paleoecology and evolution, along with the sedimentological context of the fossils. The lack of a high-resolution stratigraphic framework has hampered such study. In this paper we develop the needed stratigraphy for the areas in the Pisco Formation where most of the vertebrate paleontological research is occurring. In the Ica Valley and in the vicinity of Lomas, series of lithologically or paleontologically unique marker beds were identified. These were walked out and documented with GPS technology. Measured sections connecting these marker beds provide a stratigraphic framework for the areas studied. GPS locations, maps of the marker beds on aerial photographs, and outcrop photographs allow field determination of the stratigraphic positions of study areas.     

Currents in the Taiwan Strait as observed by surface drifters

The trajectories of 110 satellite-tracked surface drifters from 1989 to 2007 were analyzed to elucidate near-surface circulation in the Taiwan Strait. Although the summer circulation observed generally agrees with previous studies, several aspects of the winter circulation were revealed by the analyses. Unlike many earlier studies, which have suggested that a northward (southward) current prevails in the eastern (western) part of the Taiwan Strait during the northeast monsoon season, this study shows that almost all winter drifters that entered the Taiwan Strait eventually moved southward. Inside the Taiwan Strait, northward moving tracks can only be found in the Penghu Channel. After passing the Penghu Channel, the drifters were blocked by the northeast monsoon wind and the Yun-Chang Rise, and turned southward. None of the drifters flowed persistently northward through the Taiwan Strait in winter. In the southern Taiwan Strait, three typical patterns of circulation were observed for the winter trajectories—the “throughflow” pattern that enters the South China Sea flowing westward along the slope; the loop current pattern that circulates anticyclonically and returns to the Kuroshio; and the blocked intrusion pattern that penetrates into the Taiwan Strait through the Penghu Channel.     

The Inner Ear and its Coupling to the Swim Bladder in the Deep-Sea Fish Antimora rostrata (Teleostei: Moridae)

The inner ear structure of Antimora rostrata and its coupling to the swim bladder were analyzed and compared with the inner ears of several shallow-water species that also have similar coupling. The inner ear of Antimora has a long saccular otolith and sensory epithelium as compared to many other fishes. Some parts of the membranous labyrinth are thick and rigid, while other parts are thinner but attached tightly to the bony capsule. The partially rigid membranous labyrinth, along with its intimate connection to the swim bladder, may help the inner ear follow the sound oscillations from the swim bladder with better precision than would occur in a less rigid inner ear. In addition, the saccular sensory epithelium has an elaborate structure and an anterior enlargement that may be correlated with increased hearing sensitivity. Some of the features in the inner ear of Antimora may reflect the functional specialization of deep-water living and support the hypothesis that there is enhanced inner ear sensitivity in some deep-sea fishes.     

A model for developing best practice volcano monitoring: a combined threat assessment,consultation and network effectiveness approach

This paper presents a combined approach to achieving best practice volcano monitoring through a review of New Zealand’s volcano-monitoring capability as established under the GeoNet project. A series of benchmark, consultation and network performance studies were undertaken to provide a comprehensive review of volcano monitoring in New Zealand and to establish plans for future improvements in capability. The United States Geological Survey National Volcano Early Warning System method was applied to benchmark the established monitoring networks against recommendations for instrumentation based on a volcano’s threat level. Next, a consultative study of New Zealand’s volcanology research community was undertaken to canvass opinions on what future directions GeoNet volcano monitoring should take. Once the seismic network infrastructure had been built, a noise floor analysis was conducted to identify stations with poor site noise characteristics. Noise remediation for poor sites has been implemented by either re-locating the site or placing sensors in boreholes. Quality control of Global Navigation Satellite System networks is undertaken through the use of multipath parameters derived from routine processing. Finally, the performance of the monitoring networks is assessed against two recent eruptions at Mount Tongariro and White Island. This combined approach can be used as a model to assess the need for future monitoring levels on any volcano.     

Quantifying shoreline change in Funafuti Atoll,Tuvalu using a time series of Quickbird,Worldview and Landsat data

Funafuti Atoll, Tuvalu is located in the southwestern Pacific Ocean, which has experienced some of the highest rates of global sea-level rise over the past 60 years. Atoll islands are low-lying accumulations of reef-derived sediment that provide the only habitable land in Tuvalu, and are considered vulnerable to the myriad possible impacts of climate change, especially sea-level rise. This study examines the shoreline change of twenty-eight islands in Funafuti Atoll between 2005 and 2015 using 0.65 m QuickBird, 0.46 m WorldView-2, and 0.31 m WorldView-3 imagery using an image segmentation and decision tree classification. Shoreline change estimates are compared to previous study that used a visual interpretation approach. The feasibility of estimating island area with Landsat-8 Operational Land Imager (OLI) data is explored using CLASlite software. Results indicate a 0.13% (0.35 ha) decrease in net island area over the study time period, with 13 islands decreasing in area and 15 islands increasing in area. Substantial decreases in island area occurred on the islands of Fuagea, Tefala and Vasafua, which coincides with the timing of Cyclone Pam in March, 2015. Comparison between the WorldView-2 shoreline maps and those created from Landstat-8 indicate that the estimates tend to be in higher agreement for islands that have an area > 0.5 ha, a compact shape, and no built structures. Ten islands had > 90% agreement, with percent disagreements ranging from 2.78 to 100%. The methods and results of this study speak to the potential of automated EoV shoreline monitoring through segmentation and classification tree approach, which would reduce down data processing and analysis time. With the growing constellation of high and medium spatial resolution satellite-based sensors and the development of semi or fully automated image processing technology, it is now possible to remotely assess the short and medium-term shoreline dynamics on dynamic atolls. Landsat estimates were reasonably matched to those derived from fine resolution imagery, with some caveats about island size and shape.     

基于遥感的海表紫外辐射强度反演方法

Ultraviolet(UV) radiation has a significant influence on marine biological processes and primary productivity;however, the existing ocean color satellite sensors seldom contain UV bands. A look-up table of wavelengthintegrated UV irradiance(280–400 nm) on the sea surface is established using the coupled ocean atmosphere radiative transfer(COART) model. On the basis of the look-up table, the distributions of the UV irradiance at middle and low latitudes are inversed by using the satellite-derived atmospheric products from the Aqua satellite,including aerosol optical thickness at 550 nm, ozone content, liquid water path, and the total precipitable water.The validation results show that the mean relative difference of the 10 d rolling averaged UV irradiance between the satellite retrieval and field observations is 8.20% at the time of satellite passing and 13.95% for the daily dose of UV. The monthly-averaged UV irradiance and daily dose of UV retrieved by satellite data show a good correlation with the in situ data, with mean relative differences of 6.87% and 8.43%, respectively. The sensitivity analysis of satellite inputs is conducted. The liquid water path representing the condition of cloud has the highest effect on the retrieval of the UV irradiance, while ozone and aerosol have relatively lesser effect. The influence of the total precipitable water is not significant. On the basis of the satellite-derived UV irradiance on the sea surface, a preliminary simple estimation of ultraviolet radiation's effects on the global marine primary productivity is presented, and the results reveal that ultraviolet radiation has a non-negligible effect on the estimation of the marine primary productivity.     

黑潮水对台湾海峡东南部源水的影响：数值结果

Model output from a Pacific basin-wide three-dimensional physical-biogeochemical model during the period of 1991 to 2008 was used to investigate the impact of Kuroshio water on the source water of the southeastern Taiwan Strait. Based on the characteristic salinities of both Kuroshio water and the South China Sea water, a Kuroshio impact index (KII) was designed to measure the degree of impact. The KII correlates significantly with the northeast-southwest component of wind stress, but the former lags the latter by approximately two months. The correlation coefficient between them increases from 0.267 4 to 0.852 9, with a lag time increasing from 0 to 63 days. The impact of Kuroshio Water is greater in winter and spring than in summer and autumn. At the interannual time scale, El Niño and La Niña events play an important role in impacting the KII. During El Niño events, more Kuroshio water contributes to the source water of the southeastern Taiwan Strait. Conversely, during La Niña events, less Kuroshio water contributes to the source water.