Evaluating Hyperspectral Imager for the Coastal Ocean (HICO) data for seagrass mapping in Indian River Lagoon,FL     

Hyun Jung Cho  Igor Ogashawara  Deepak Mishra  Joseph White  Andrew Kamerosky  Lori Morris 《地理信息系统科学与遥感》2014,51(2):120-138

Differentiation between benthic habitats, particularly seagrass and macroalgae, using satellite data is complicated because of water column effects plus the presence of chlorophyll-a in both seagrass and algae that result in similar spectral patterns. Hyperspectral imager for the coastal ocean data over the Indian River Lagoon, Florida, USA, was used to develop two benthic classification models, Slope_RED and Slope_NIR. Their performance was compared with iterative self-organizing data analysis technique and spectral angle mapping classification methods. The slope models provided greater overall accuracies (63–64%) and were able to distinguish between seagrass and macroalgae substrates more accurately compared to the results obtained using the other classifications methods.  相似文献   

Characteristics of Seafloor Morphology and Ferromanganese Nodule Occurrence in the Korea Deep-sea Environmental Study (KODES) Area,NE Equatorial Pacific     

Hoi-Soo Jung  Young-Tak Ko  Sang-Bum Chi  Jai-Woon Moon 《Marine Georesources & Geotechnology》2013,31(3):167-180

Abstract

Seafloor morphology and ferromanganese nodule occurrence were studied using a multibeam side scan sonar (SeaBeam, 2000) and a deep-sea camera system in the Korea Deep-sea Environmental Study (KODES) area, northeast equatorial Pacific. Seafloor morphology and nodule abundance are highly variable even in this small study area. The NNE-SSW oriented hills are parallel and about 100–200 m high. Valleys are very flat-floored, while hilltops are rugged with depressions of tens of meters. Cliffs to about 100 m bound the valleys and the hills. The study area can be classified into three types based both on nodule occurrence and seafloor morphology, mostly G- and B-types and some M-type. G-type is characterized by high nodule abundance, ubiquitous bioturbation, and flat seafloor morphology, while B-type is characterized by irregular-shaped nodules, variable nodule abundance, occurrence of giant nodules and sediment lumps, rugged bottom morphology with depressions, and white calcareous surface sediments. Medium nodule abundance and a generally flat seafloor characterize M-type. G-type occurs mostly in the valley regions, while B-type is on the hilltop areas. M-type is located between the hilltop and the valley. Tectonic movement of the Pacific plate resulted in the elongated abyssal hills and cliffs. The rugged morphology on hilltops resulted from erosion and redistribution of surface siliceous sediments on hilltops by bottom currents, outcropping of underlying calcareous sediments, and dissolution of the carbonate sediments by corrosive bottom water undersaturated with CaCO₃. Sediment eroded from the hills, which is relatively young and organic-rich, is deposited in the valleys, and diagenetic metal supply to manganese nodules in the valley area is more active than on the hills. We suggest that tectonic movement ultimately constrains morphology, surface sediment facies, bottom currents and sediment redistribution, bioturbation, thickness of the sedimentary layer, and other conditions, which are all interrelated and control nodule occurrence. The best potential area for mining in the study area is the G-type valley zones with about 3–4 km width and NNW-SSE orientation.  相似文献   

Gmax of Reclaimed Ground on the Western Coast of Korea Using Various Field and Laboratory Measurements     

Young-Hoon Jung  Taesik Kim 《Marine Georesources & Geotechnology》2013,31(4):351-367

The maximum shear modulus of soil is a principal parameter for the design of earth structures under static and dynamic loads. In this study, the statistical data of the maximum shear moduli of reclaimed ground in the Songdo area on the western coast of Korea were evaluated using various field and laboratory tests, including the standard penetration test (SPT), piezocone penetration test (CPTu), self-boring pressure meter test (SBPT), down-hole seismic test (DHT), seismic piezocone penetration test (SCPTu) and resonant column test (RCT). Soils were classified variously by using a conventional unified soil classification system and classification charts for CPTu data. For the soils containing mostly sand and silt, the soil classifications using the classification charts for CPTu data show good agreement with the unified soil classification. Based on the statistical analysis on various maximum shear moduli, new site-specific empirical correlations between the shear moduli and SPT and CPTu values were proposed. Predictions of the maximum shear moduli using the proposed correlations were compared with the data obtained from the DHT, which is comparatively exact in evaluating the maximum stiffness of soils. The good agreement confirmed that the proposed correlations reasonably predicted the maximum shear moduli of soils in western coastal area of Korea.  相似文献   

Marine-Derived Fungi in Korea     

Kwon  Yong Min  Bae  Seung Sub  Choi  Grace  Lim  Ji Yeon  Jung  Yoon-Hee  Chung  Dawoon 《Ocean Science Journal》2021,56(1):1-17

Ocean Science Journal - Studies on marine fungi (termed as ‘marine-derived fungi’ in this paper) have been significantly increasing worldwide because of the critical role displayed by...  相似文献   

Distribution of small plastic debris in cross-section and high strandline on Heungnam beach, South Korea     

Nak Won Heo  Sang Hee Hong  Gi Myung Han  Sunwook Hong  Jongmyoung Lee  Young Kyung Song  Mi Jang  Won Joon Shim 《Ocean Science Journal》2013,48(2):225-233

The spatial distribution of small plastic debris on Heungnam beach in February 2011 was investigated. The abundances of small plastic debris over 2 mm in size along the high strandline and cross-sectional line of the beach were determined. The mean abundances of small plastics were 976 ± 405 particles/m² at the high strandline in the upper tidal zone along the shoreline and 473 ± 866 particles/m² at the cross-section perpendicular to the shoreline. Specifically, styrofoam (expanded polystyrene) spherules accounted for 90.7% of the total plastic abundance in the high strandline and 96.3% in the cross-section. The spatial distribution patterns of small plastic debris differed between the high strandline and cross-sectional line. The cross-sectional distribution of small plastic abundance differed among plastic types, indicating that representative sampling of small plastic debris on a beach is necessary.  相似文献   

Soil–gas monitoring: A tool for fault delineation studies along Hsinhua Fault (Tainan), Southern Taiwan     

Vivek Walia  Shih Jung Lin  Ching Chou Fu  Tsanyao Frank Yang  Wei-Li Hong  Kuo-Liang Wen  Cheng-Hong Chen 《Applied Geochemistry》2010

Many studies have shown the soil gas method to be one of the most reliable investigation tools in the research of earthquake precursory signals and fault delineation. The present research is aimed finding the relationship between soil gas distribution and tectonic systems in the vicinity of the Hsinhua Fault zone in the Tainan area of Southern Taiwan. More than 110 samples were collected along 13 traverses to find the spatial distribution of Rn, He, CO₂ and N₂. The spatial congruence of all the gases shows that N₂ is the most probable carrier gas of He, whereas CO₂ seems to be a good carrier gas of Rn in this area. From the spatial distribution of Rn, He, CO₂ and N₂ the trace of Hsinhua Fault and neotectonic features can be identified. The spatial distribution of studied gases shows a clear anomalous trend ENE–SWS along the Hsinhua Fault.  相似文献   

Arctic margin gravity highs: Deeper meaning for sediment depocenters?     

Vogt  Peter R.  Jung  Woo-Yeol  Brozena  John 《Marine Geophysical Researches》1998,20(5):459-477

Morphologic, gravity, and seismic reflection/refraction data from ca. 10,000 km of Arctic passive continental margins suggest that the numerous oval free-air gravity anomalies, their +50–150 mGal extrema typically located just landward of shelf breaks, are caused by combinations of rapidly deposited Plio-Pleistocene glacial marine sediment loads, older post-breakup sediments, and perhaps causally related density anomalies (mascons) in the underlying oceanic crust. Dispersed seismicity associated with some gravity highs may reflect ongoing brittle, flexural adjustment to the loads. Multi-channel-seismic-controlled depocenter models for several prominent highs (including the Hornsund gravity high re-examined here) suggest that sediments alone do not suffice to explain the gravity highs, unless depocenter seismic velocities have been significantly underestimated. A flexural backstripping model for the Hornsund anomaly only roughly replicates observed gravity. Subjacent 'mascons', if present below some depocenters, may be caused by (1) anomalous subsidence of initially formed dense/thin crust; (2) depocenter blanketing of early-formed crust, mitigating hydrothermal fracturing and related density reduction; or (3) metastable phase transitions, converting basalt/gabbro to denser phases (Neugebauer–Spohn hypothesis), while cracks close or fill under the increased pressures and temperatures.  相似文献   

Bioremediation of contaminated coastal sediment: Optimization of slow release biostimulant ball using response surface methodology (RSM) and stabilization of metals from contaminated sediment     

Bakthavachallam Subha  Young Chae Song  Jung Hui Woo 《Marine pollution bulletin》2017,114(1):285-295

The aim of the present study is to optimize the slow release biostimulant ball (BSB) for bioremediation of contaminated coastal sediment using response surface methodology (RSM). Metals contamination and stabilization of metals in coastal sediments using BSB were investigated. The effects of BSB size (1–5 cm), distance (1–10 cm), and time (1–4 months) on the stabilization of metals including Fe, Cd, Cu, and Pb were determined. The maximum stabilization percentages of Fe, Cd, Cu, and Pb, of 64.5%, 54.9%, 63.8%, and 47.6%, respectively, were observed at a 3 cm ball size, 5.5 cm distance, and a period of 4 months; these values are the optimum conditions for effective treatment of contaminated coastal sediment. The determination coefficient of the R² value suggests that > 91.55%, 89.97%, 96.10%, and 86.40% of the variance is attributable to the variables of Fe, Cd, Cu, and Pb, respectively.  相似文献