长江中下游地区地震活动与洪涝灾害关系探讨

大量例证说明,地震在一定程度上与洪涝 (强降水)存在着某种联系。流体对岩石的渗透作用, 地球的热动力学作用,大气低压对岩石孔隙气体和液体的吸取作用,基于地质构造的触发作用等,可能是地震与洪涝(强降水)相互存在一定关联的原因。长江中下游地区水系丰富,湖泊众多,是我国洪涝多发区,该区还存在着中强地震的活动,开展地震活动与洪涝灾害关系的研究,预测地震活动与洪涝灾害同步达到高峰的时间、相互作用强度等有利于长江中下游地区综合减灾工作。     

Modeling Uranian mutual event light curves

Salient features of the analysis of the mutual event light curves of planetary satellites are presented. The need to carefully evaluate the flux contribution of the occulting/eclipsing satellite to the total flux is illustrated. Albedo variations on the satellites will produce signatures on the mutual event light curves. The partial events of the upcoming mutual event series of the uranian satellites can be modeled taking into account the albedo variations inferred from the maps of the southern regions imaged by Voyager 2 when only these regions are occulted/eclipsed. This will enable a robust determination of the astrometric parameters. The shape and asymmetry of the mutual event light curves along with the rotational light curves of the satellites obtained simultaneously during the planet's equinox crossing period can be utilized to obtain a coarse albedo map of the northern hemisphere of the satellites. These studies will also help in investigating possible changes in the known southern regions since the 1986 encounter of Voyager 2.     

Dynamical objectives of observation of mutual events

Recently the motion of the main satellites of Jupiter, Saturn and Uranus have been modelled in order to get accurate ephemerides. These models have been fitted over a large amount of observations. Among these ones, the positions issued from the observations of mutual events are the most accurate. We can then expect to obtain a new kind of dynamical informations directly linked to planetological questions. We have to determine what information is used in these observations to get the still unknown dynamical parameters. We look after these questions especially in the Jovian and Saturnian systems.