Seismicity in northern Arizona is concentrated in a northwest-southeast trending belt that stretches from the Utah border south to the edge of the Colorado Plateau. Located within this NASB （Northern Arizona Seismic ...Seismicity in northern Arizona is concentrated in a northwest-southeast trending belt that stretches from the Utah border south to the edge of the Colorado Plateau. Located within this NASB （Northern Arizona Seismic Belt） is the San Francisco volcanic field, classified by the United States Geological Survey as potentially active. The last volcanic event in the field was located at Sunset Crater and occurred less than 1,000 years ago. Eruption intervals in the volcanic field are of the same order of length of time. Seismic monitoring of the volcanic field area has improved greatly since 1985 with the establishment of new network seismic stations. This has allowed for a lowered threshold of detection of seismic events and improved location capabilities. As an example of the result of this improved ability to locate smaller tremors, two swarms have been identified in the field, the 2009 Halloween swarm near Sunset Crater volcano and the 2011 swarm near Flagstaff, the largest urban community in northern Arizona.展开更多
Based on the digital seismic waveform data observed from regional and reservoir seismic networks,the seismicity and source parameters in the Zipingpu reservoir area from January 1,2000 to May 11,2008 before the Wenchu...Based on the digital seismic waveform data observed from regional and reservoir seismic networks,the seismicity and source parameters in the Zipingpu reservoir area from January 1,2000 to May 11,2008 before the Wenchuan MS8.0 earthquake are studied. The analysis shows a continuous activity of small earthquakes before the Wenchuan MS8. 0 earthquake. The level of seismic activity was from ML2.0 to ML3.0 in recent years. The impoundment of Zipingpu reservoir started in September 2005 and the obvious increment of seismic activities occurred in February 2008,but according to the analysis of the longer time series,the frequency and intensity of seismic activities do not exceed its range,which means it is still a fluctuation of regional seismic activities or tectonic activity. At the same time,we also studied the spatio-temporal distribution and the change of apparent stress difference in the source region before the great earthquake,and the results show that the apparent stress values of small earthquakes are generally higher than fitted values of apparent stress in the reservoir area in the nearly three months before the Wenchuan MS8.0 earthquake. It can be seen from the spatial distribution of apparent stress difference,that the epicenter of the earthquake is located at a low stress distribution area,and the relatively high apparent stress difference is at the east of the epicenter. Apparent stress increment occurred in local areas.展开更多
The economies during the post-industrial era are returning to the classical meaning of manufacturing sector in the process of balanced regional growth and are searching for stimuli for diversifying economic structure ...The economies during the post-industrial era are returning to the classical meaning of manufacturing sector in the process of balanced regional growth and are searching for stimuli for diversifying economic structure and reindustrialization. Expansion of a new growth theory highlighted the necessity for the well-developed so-called innovative manufacturing sector; however, stimuli for realizing the potential of this sector are limited due to relative attractiveness of sectors with lower risks and faster returns especially in regions followers. Moreover, regional success as a result of the previous development can hinder changes and stimulate economic agents to avoid regions and sectors with high potential but weak performance. Generation of regional economic growth can be considered in a framework of two kinds of stimuli as financial and structural. Financial capital as an important factor for supporting structural change in economy helps to stay in harmony with the modern economy; however, existing sectoral composition can be persistent to changes. Latvia is considered as a case study about issues on fmancial and structural stimuli for regional growth because of the bright dominance of capital city region （high regional differentiation） and typical post-industrial economic structure in parallel with an intention to actively participate in reindustrialization and increase the innovativeness of economy. This article searches whether foreign investment stock in a company＇s equity capital provides a stimulus for an industrial change at a micro level （five regions and 12 manufacturing sectors in accordance with statistical classification of economic activities NACE 2 Rev. （Nomenclature generale des Activities economiques dans les Communuates Europeennes） two-digit level） and whether this change contributes to the regional growth. Unbalanced regional growth as a result of reallocation of financial resources among sectors of economic activity and differences in distribution of economic success at a sectoral level provide a useful foundation for testing the impact of foreign direct investments （FDI） on changes in economic structure.展开更多
文摘Seismicity in northern Arizona is concentrated in a northwest-southeast trending belt that stretches from the Utah border south to the edge of the Colorado Plateau. Located within this NASB （Northern Arizona Seismic Belt） is the San Francisco volcanic field, classified by the United States Geological Survey as potentially active. The last volcanic event in the field was located at Sunset Crater and occurred less than 1,000 years ago. Eruption intervals in the volcanic field are of the same order of length of time. Seismic monitoring of the volcanic field area has improved greatly since 1985 with the establishment of new network seismic stations. This has allowed for a lowered threshold of detection of seismic events and improved location capabilities. As an example of the result of this improved ability to locate smaller tremors, two swarms have been identified in the field, the 2009 Halloween swarm near Sunset Crater volcano and the 2011 swarm near Flagstaff, the largest urban community in northern Arizona.
基金sponsored by the research project on reservoir earthquake monitoring and prediction technique (2008BAC38B03-02),China
文摘Based on the digital seismic waveform data observed from regional and reservoir seismic networks,the seismicity and source parameters in the Zipingpu reservoir area from January 1,2000 to May 11,2008 before the Wenchuan MS8.0 earthquake are studied. The analysis shows a continuous activity of small earthquakes before the Wenchuan MS8. 0 earthquake. The level of seismic activity was from ML2.0 to ML3.0 in recent years. The impoundment of Zipingpu reservoir started in September 2005 and the obvious increment of seismic activities occurred in February 2008,but according to the analysis of the longer time series,the frequency and intensity of seismic activities do not exceed its range,which means it is still a fluctuation of regional seismic activities or tectonic activity. At the same time,we also studied the spatio-temporal distribution and the change of apparent stress difference in the source region before the great earthquake,and the results show that the apparent stress values of small earthquakes are generally higher than fitted values of apparent stress in the reservoir area in the nearly three months before the Wenchuan MS8.0 earthquake. It can be seen from the spatial distribution of apparent stress difference,that the epicenter of the earthquake is located at a low stress distribution area,and the relatively high apparent stress difference is at the east of the epicenter. Apparent stress increment occurred in local areas.
文摘The economies during the post-industrial era are returning to the classical meaning of manufacturing sector in the process of balanced regional growth and are searching for stimuli for diversifying economic structure and reindustrialization. Expansion of a new growth theory highlighted the necessity for the well-developed so-called innovative manufacturing sector; however, stimuli for realizing the potential of this sector are limited due to relative attractiveness of sectors with lower risks and faster returns especially in regions followers. Moreover, regional success as a result of the previous development can hinder changes and stimulate economic agents to avoid regions and sectors with high potential but weak performance. Generation of regional economic growth can be considered in a framework of two kinds of stimuli as financial and structural. Financial capital as an important factor for supporting structural change in economy helps to stay in harmony with the modern economy; however, existing sectoral composition can be persistent to changes. Latvia is considered as a case study about issues on fmancial and structural stimuli for regional growth because of the bright dominance of capital city region （high regional differentiation） and typical post-industrial economic structure in parallel with an intention to actively participate in reindustrialization and increase the innovativeness of economy. This article searches whether foreign investment stock in a company＇s equity capital provides a stimulus for an industrial change at a micro level （five regions and 12 manufacturing sectors in accordance with statistical classification of economic activities NACE 2 Rev. （Nomenclature generale des Activities economiques dans les Communuates Europeennes） two-digit level） and whether this change contributes to the regional growth. Unbalanced regional growth as a result of reallocation of financial resources among sectors of economic activity and differences in distribution of economic success at a sectoral level provide a useful foundation for testing the impact of foreign direct investments （FDI） on changes in economic structure.
