The Relation between Tectonic Movement and Climatic Change

Climate and tectonics are two interactive factors in the earth’s system. They are controlled by astronomical cy-cles. It has been unheeded for a long time that large-scale material motion caused by global climatic change is one of the powers for tectonic movement. Tectonic movement makes the distributional pattern of continent and ocean change and makes global climate type change strongly in large scale. It is a good example that the change of the sea-ice around Antarctic Continent and in the Drake Passage has the switch process for global climatic changes. Tide makes the oceanic crust of the East Pacific Ocean and the West Pacific Ocean rise or fall 60 cm oppositely. Before and after El Nino events, the oceanic level of the East Pacific Ocean and the West Pacific Ocean may rise or fall 40 cm oppositely. Because of isostasy, oceanic crust may fall or rise 13 or 20 cm. They are the reasons why El Nino events are interrelated with the earthquakes and volcanoes. This is so called seesaw phenomenon of oceanic crust.

Strong Tides in 1964 and 1982

The differential rotation between solid and fluid caused by tidal force can explain a 1 500 to 1 800-year cycle of the climate change. Strong tide increases the vertical and horizontal mixing of water in ocean by drawing the cold Pacific water from the depths to the surface (or by making the warm water flow from the West Pacific to the East as well as from the North to the South). It cools or warms the atmosphere above and makes La Nina or El Nino occur in the whole world. Astronomical data have shown that strong tide is often associated with El Nino events. Volcanic activities at sub-marine are also controlled by strong tide. Volcanic activities can also draw warm water from the depths to the surface in the Pacific and volcanic ash can keep out sunlight, which is the most important external forcing factor for El Nino. If vol-canic ash reaches into the stratosphere, finer aerosols will spread throughout the globe during a few months and will float in it for one to three years to weaken the sun’s direct radiation to the areas. It is one of the factors to postpone EI Nino just like the process of solar eclipse.

Image and data processing of digital zenith telescope(DZT-1) of China

The first digital zenith telescope prototype(DZT-1)of China was successfully developed by National Astronomical Observatories,Chinese Academy of Sciences and Shandong University of Science and Technology at the end of 2011.Compared with classical astrometric telescopes,DZT-1 has features of small size,high automation,and high accuracy.It can be used to do classical astrometric observations as well as measurement of plumb line variation and deflection of the vertical.So DZT-1 plays a significant role in astronomy and geoscience.Although the measurement principle and method of DZT-1 are somewhat similar to classical photographic zenith tube,there are still many differences.The present paper introduces the principle,method,and procedure for processing DZT-1 star image and data,as well as the application software for astronomical latitude and longitude calculation using DZT-1 observations.The test observations and the observation results are also presented.According to the test observation results,the standard deviation of single observation is about 0.200–0.300,and 0.0700–0.0800in term of a group observations.In conclusion,the data processing software fulfills DZT-1’s demand for data processing,guaranteeing the automation and high accuracy for DZT-1.