Tih and strain meters of the deformation-observation network in Hubei Province all responded to the Mw9.0 Japan earthquake on March 11,2011. By analyzing the co-seismic responses,we found that firstly there was essent...Tih and strain meters of the deformation-observation network in Hubei Province all responded to the Mw9.0 Japan earthquake on March 11,2011. By analyzing the co-seismic responses,we found that firstly there was essentially a linear correlation between response time and epicentral distance. Secondly, there was some correlation between maximum response amplitude and earthquake magnitude as well as between the duration and earthquake magnitude. Thirdly, the response amplitudes and decay rates were different for different types of instruments. Due to less data-sampling frequency, the deformation instruments, could not display the first motion of P and S waves, but responded mainly to far-field surface waves. Before the earthquake, the NS earthtide component recorded by the cave stainmeter at Yichang was distorted for nearly eight hours. While digital deformation observation did not show complete information about the earthquake source, it still reflected some key features of seismic-wave propagation.展开更多
In order to investigate the isotopic and chemical characteristics of lagoon waters in Niigata Prefecture in recent years, oxygen and hydrogen stable isotope ratios （i.e., 8180 and 6D）, the concentrations of DOC （di...In order to investigate the isotopic and chemical characteristics of lagoon waters in Niigata Prefecture in recent years, oxygen and hydrogen stable isotope ratios （i.e., 8180 and 6D）, the concentrations of DOC （dissolved organic carbon）, DO （dissolved oxygen） and pH, etc. in water samples of Sakata and Toyanogata were measured. Samples were generally taken monthly at the fixed sampling points from these lagoons. Consequently, the following matters have been mainly clarified： （1） ~D value of water samples in Sakata was generally larger than that in Toyanogata similarly to the case of ~180, though remarkable large difference among samples was not found; （2） the pH value of lagoon water samples is almost 6.5-8.5 （which is generally larger than that of river water）, and pH at the spot of SI （downstream point of Lower Lagoon （Shitakata）） is remarkably high （9.0-9.5）; （3） Lagoon water has the chemical characteristics contrasting to groundwater with a focus on river water from the viewpoint of pH （acidity or alkalinity） and DO. These matters can be closely related to the biological activity such as photosynthesis due to aquatic plant and phytoplankton and the activity of Crustacea plankton etc. in lagoon.展开更多
文摘Tih and strain meters of the deformation-observation network in Hubei Province all responded to the Mw9.0 Japan earthquake on March 11,2011. By analyzing the co-seismic responses,we found that firstly there was essentially a linear correlation between response time and epicentral distance. Secondly, there was some correlation between maximum response amplitude and earthquake magnitude as well as between the duration and earthquake magnitude. Thirdly, the response amplitudes and decay rates were different for different types of instruments. Due to less data-sampling frequency, the deformation instruments, could not display the first motion of P and S waves, but responded mainly to far-field surface waves. Before the earthquake, the NS earthtide component recorded by the cave stainmeter at Yichang was distorted for nearly eight hours. While digital deformation observation did not show complete information about the earthquake source, it still reflected some key features of seismic-wave propagation.
文摘In order to investigate the isotopic and chemical characteristics of lagoon waters in Niigata Prefecture in recent years, oxygen and hydrogen stable isotope ratios （i.e., 8180 and 6D）, the concentrations of DOC （dissolved organic carbon）, DO （dissolved oxygen） and pH, etc. in water samples of Sakata and Toyanogata were measured. Samples were generally taken monthly at the fixed sampling points from these lagoons. Consequently, the following matters have been mainly clarified： （1） ~D value of water samples in Sakata was generally larger than that in Toyanogata similarly to the case of ~180, though remarkable large difference among samples was not found; （2） the pH value of lagoon water samples is almost 6.5-8.5 （which is generally larger than that of river water）, and pH at the spot of SI （downstream point of Lower Lagoon （Shitakata）） is remarkably high （9.0-9.5）; （3） Lagoon water has the chemical characteristics contrasting to groundwater with a focus on river water from the viewpoint of pH （acidity or alkalinity） and DO. These matters can be closely related to the biological activity such as photosynthesis due to aquatic plant and phytoplankton and the activity of Crustacea plankton etc. in lagoon.
