The 2000 km Columbia River is the longest river in the Pacific Northwest region of North America. It starts in British Columbia, Canada and flows through the states of Oregon and Washington before discharging into Pac...The 2000 km Columbia River is the longest river in the Pacific Northwest region of North America. It starts in British Columbia, Canada and flows through the states of Oregon and Washington before discharging into Pacific Ocean near Cape Disappointment. The mouth of the Columbia River is a deep water harbor and 180 km of the river can be accessed by navigation. Based on flow volume, the river is the 4th largest river in the United States. The headwaters and approximately 800 km of the Columbia River lie in Canada. Columbia Lake and the Columbia Wetlands are located in British Columbia and are the headwaters of the Columbia River. The lake has an elevation of 820 m above sea level and drains to the Pacific Ocean near Astoria, Oregon. The Ocean tides flow up river to Portland, Oregon. This paper highlights how the geological and landscape resources of the Columbia River and tributaries watershed contributed to the economic development of this historically rich region of North America. The Columbia River is one of the most biologically diverse freshwater systems in the United States. The Columbia River system with trails and cruise ships was designed to increase use of the Columbia River, to promote recreational tourism, and to create a generation of people who are willing to protect and provide environmental stewardship of the river basin resources.展开更多
1研究背景跨越中朝边境的长白山天池火山是亚洲乃至全球庞大且极具危险性的复合型活火山之一,备受全球关注。圣海伦斯火山(St.Helens)是北美喀斯喀特火山链上的一座大型层状火山,1980年大喷发是全球火山喷发研究最详细的一次喷发(Lipman...1研究背景跨越中朝边境的长白山天池火山是亚洲乃至全球庞大且极具危险性的复合型活火山之一,备受全球关注。圣海伦斯火山(St.Helens)是北美喀斯喀特火山链上的一座大型层状火山,1980年大喷发是全球火山喷发研究最详细的一次喷发(Lipman et al,1981),其火山喷发活动反映了复杂的岩浆作用过程(Bailey et al,1983)。不同构造环境产生不同类型的火山,不同类型的火山具有不同的喷发方式,会造成不同类型与不同程度的灾害。展开更多
文摘The 2000 km Columbia River is the longest river in the Pacific Northwest region of North America. It starts in British Columbia, Canada and flows through the states of Oregon and Washington before discharging into Pacific Ocean near Cape Disappointment. The mouth of the Columbia River is a deep water harbor and 180 km of the river can be accessed by navigation. Based on flow volume, the river is the 4th largest river in the United States. The headwaters and approximately 800 km of the Columbia River lie in Canada. Columbia Lake and the Columbia Wetlands are located in British Columbia and are the headwaters of the Columbia River. The lake has an elevation of 820 m above sea level and drains to the Pacific Ocean near Astoria, Oregon. The Ocean tides flow up river to Portland, Oregon. This paper highlights how the geological and landscape resources of the Columbia River and tributaries watershed contributed to the economic development of this historically rich region of North America. The Columbia River is one of the most biologically diverse freshwater systems in the United States. The Columbia River system with trails and cruise ships was designed to increase use of the Columbia River, to promote recreational tourism, and to create a generation of people who are willing to protect and provide environmental stewardship of the river basin resources.
文摘1研究背景跨越中朝边境的长白山天池火山是亚洲乃至全球庞大且极具危险性的复合型活火山之一,备受全球关注。圣海伦斯火山(St.Helens)是北美喀斯喀特火山链上的一座大型层状火山,1980年大喷发是全球火山喷发研究最详细的一次喷发(Lipman et al,1981),其火山喷发活动反映了复杂的岩浆作用过程(Bailey et al,1983)。不同构造环境产生不同类型的火山,不同类型的火山具有不同的喷发方式,会造成不同类型与不同程度的灾害。
