Water Loads and Its Effect on Basin Subsidence

Basin subsidence can be induced by many factors, such as tectonic activity, sedimentary loading, and water loading, and so on. This paper puts forward a concept of water loads subsidence, deduces a calculation formula of water loads subsidence, quantitatively analyzes the contribution of water loads to basin subsidence. Furthermore, fully considering the effects of sediment loads,water loads,sea-level changes, and paleao-water depth on basin subsidence, this paper gives a revision to the formula used to calculate the tectonic subsidence by Steckler and Watts. The quantitative analysis of the COST B-2 well located in Atlantic-type continental margin of New York, U.S.A indicated that each 1km tectonic subsidence can simultaneously results in 0.435 km water loads subsidence, the true tectonic subsidence that removed water loads effect on basin subsidence is about 30.3% lower than the result calculated using Steckler and Watts formula. So, we can conclude that water loads are one of the important factors, which result in the intensive subsidence of Atlantic-type continental margin.