Day 4 Thu, September 23, 2010最新文献_第2页

Automated Detection of Hazardous Sea Ice Features from Upward Looking Sonar Data 从向上看声纳数据自动检测危险海冰特征

Day 4 Thu, September 23, 2010 Pub Date : 2010-09-20 DOI: 10.5957/icetech-2010-150

D. Fissel, A. Kanwar, K. Borg, T. Mudge, J. Marko, A. Bard

{"title":"Automated Detection of Hazardous Sea Ice Features from Upward Looking Sonar Data","authors":"D. Fissel, A. Kanwar, K. Borg, T. Mudge, J. Marko, A. Bard","doi":"10.5957/icetech-2010-150","DOIUrl":"https://doi.org/10.5957/icetech-2010-150","url":null,"abstract":"Upward-looking sonar (ULS) instruments provide extended continuous measurements of ice thicknesses and ice velocities data that are important for establishing metocean design criteria related to oil and gas operations in areas with seasonal or year-round ice cover. This paper describes the development of algorithms for the detection and measurement of hazardous ice features including: large individual ice keels with thicknesses of 5 to well over 20 m; long sections of thick hummocky (rubble) sea ice; and occurrences of multi-year ice floes. Large individual ice keels are detected using an ice draft threshold technique to identify very thick ice floes which are then categorized as to total width using a Rayleigh criteria and/or a minimum user specified threshold value (e.g. 2 m). The detection of thick hummocky ice is based on minimum criteria of ice draft data segments having median values exceeding 2.5 m and segment lengths exceeding 100 m. For qualifying segments, a selection parameter γ, defined as the 90th percentile over the 50th percentile value of ice drafts divided by the standard deviation was computed; hummocky ice is characterized by γ > 2 and is also very common for 1.5< γ <2. Results from the ongoing algorithm development for detection of multi-year ice features will also be discussed. Ice velocities can also pose difficulties for offshore oil and gas operations in terms of floating drilling platform station keeping when particularly large ice speeds occur and/or ice drift directions changing rapidly or erratically.","PeriodicalId":170517,"journal":{"name":"Day 4 Thu, September 23, 2010","volume":"2 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2010-09-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"120840967","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 4

Mapping Sea Ice Overflood Along the Alaskan North Coast 绘制阿拉斯加北海岸海冰泛滥的地图

Day 4 Thu, September 23, 2010 Pub Date : 2010-09-20 DOI: 10.5957/icetech-2010-163

D. Dickins, G. Hearon, K. Morris

引用次数: 0

Using Position Beacons to Measure Ice Movement for Beaufort and Chukchi Offshore Petroleum Activities 利用位置信标测量波弗特和楚科奇海上石油活动的冰运动

Day 4 Thu, September 23, 2010 Pub Date : 2010-09-20 DOI: 10.5957/icetech-2010-139

S. Tiffin, R. Pilkington, M. Edgecombe, D. Mcgonigal

引用次数: 2

Supporting Arctic operations with real-time ice information from satellite images 利用卫星图像提供的实时冰况信息支持北极行动

Day 4 Thu, September 23, 2010 Pub Date : 2010-09-20 DOI: 10.5957/icetech-2010-126

R. Hall

引用次数: 0

Lifeboat Habitability and Effects on Human Subjects 救生艇可居住性及其对人类受试者的影响

Day 4 Thu, September 23, 2010 Pub Date : 2010-09-20 DOI: 10.5957/icetech-2010-180

J. Power, António Simões Ré

{"title":"Lifeboat Habitability and Effects on Human Subjects","authors":"J. Power, António Simões Ré","doi":"10.5957/icetech-2010-180","DOIUrl":"https://doi.org/10.5957/icetech-2010-180","url":null,"abstract":"Lifeboats are the most used marine evacuation craft in both the shipping and offshore industries. The International Maritime Organization (IMO) Lifesaving Appliances (LSA) code does not have criteria for the manoeuvring performance of lifeboats nor for their habitability and effects on human subjects. During standard seakeeping exercises conducted with a SOLAS approved 20-person lifeboat in Conception Bay, NL two NRC employees (coxswain and assistant) wearing certified immersion suit systems had their skin temperature, deep body temperature, and heart rate measured while performing their assigned duties. During the morning of July 24th, 2009, the outside air temperature was 14°C and the water temperature was approximately 7.6°C, with little to no cloud cover. While piloting the lifeboat with the hatches closed, the interior temperature of the lifeboat rose from 19.4°C to 28.5°C over the course of approximately two hours. With the immersion suits fully zipped, the coxswain experienced an increase in mean skin temperature of 3.4°C, while the assistant’s rose by 2.7°C. The coxswain’s mean body temperature rose by 0.74°C, and the assistant’s by 1.0°C. After the two-hour time period, both the coxswain and assistant’s clothing were heavily soaked with sweat, and both reported moderate levels of thermal discomfort due to the heat. In the afternoon of the same day, with little to no cloud cover, the outside air and water temperatures registered 15°C and 8.78°C, respectively. For the afternoon trials, the lifeboat hatches were left open, and the immersion suits were unzipped. Over a two-hour period, the interior temperature of the lifeboat rose by only 0.2°C, the coxswain’s mean skin temperature rose by 0.5°C, and the assistant’s by 0.5°C. After the two hour afternoon session was completed, both the coxswain and the assistant reported little to no thermal discomfort with the interior temperature of the lifeboat. Based on these preliminary observations, prolonged occupancy of a sealed lifeboat with a high level of clothing insulation may lead to increased thermal stress on the evacuees.","PeriodicalId":170517,"journal":{"name":"Day 4 Thu, September 23, 2010","volume":"69 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2010-09-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122216109","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 4

Training Courses for Ice experts as Ice Observers and for Interpretation of Satellite Images to support Arctic Shipping Operations 为作为冰观察员的冰专家和为支持北极航运作业而解译卫星图像的培训课程

Day 4 Thu, September 23, 2010 Pub Date : 2010-09-20 DOI: 10.5957/icetech-2010-185

G.A.N. Thomas, Y. Mironov, V. Smirnov, Valery V. Stepanov

引用次数: 0

On the Spatial and Temporal Characterization of Motion Induced Sea Ice Internal Stress 运动诱发海冰内应力的时空特征研究

Day 4 Thu, September 23, 2010 Pub Date : 2010-09-20 DOI: 10.5957/icetech-2010-166

J. Hutchings, C. Geiger, A. Roberts, J. Richter-Menge, B. Elder

{"title":"On the Spatial and Temporal Characterization of Motion Induced Sea Ice Internal Stress","authors":"J. Hutchings, C. Geiger, A. Roberts, J. Richter-Menge, B. Elder","doi":"10.5957/icetech-2010-166","DOIUrl":"https://doi.org/10.5957/icetech-2010-166","url":null,"abstract":"In April 2007 an array of buoys was deployed in the Beaufort Sea with one aim (among others) of examining the relationship between internal ice stress and ice pack strain-rate or deformation. Here we present preliminary analysis of stress data from this experiment. This analysis is discussed in the context of strain-rate analysis that has been performed previously. In order to identify ice motion induced stress from stress measurements recorded at a point in the ice pack, we first need to remove the thermal stress signal from the measurement time series. We introduce a conceptual model of thermal stresses to support a method of extracting ice motion induced stress from stress buoy data. The model will require independent verification, which we outline, however is useful for understanding our results. In this paper we focus on spectral and scaling analysis of ice motion induced stresses, and compare these to similar analysis of sea ice strain-rate. By comparing spectral properties of stress and divergence we estimate that dynamic stress events (such as ridge building) may be felt at a stress sensor up to 45km from the site of deformation. Ice motion induced stresses demonstrate fractal scaling properties, and are anti-persistent. This echoes similar results that have been identified for sea ice strain rate across spatial scales from 10 to 1000 km. Ice motion induced stress and sea ice strain rate can not be described by Gaussian statistics, and have “fat tailed” probability distribution functions. These findings provide insight into how to model risk of large deformation, with large ice motion induced stress, events impacting any given place in the Arctic ice pack.","PeriodicalId":170517,"journal":{"name":"Day 4 Thu, September 23, 2010","volume":"26 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2010-09-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121401399","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 1

Assessment of Lifeboat Laminate Strength 救生艇层压板强度评估

Day 4 Thu, September 23, 2010 Pub Date : 2010-09-20 DOI: 10.5957/icetech-2010-152

P. Gifford, A. Kennedy

引用次数: 0