MEMS Sensor Network for Submarine Terrain and Strata Deformation Monitoring: Design and Field Experiment

The deformation monitoring of terrain and shallow strata is important to the gas hydrate mining environment and the early warning of seabed instabilities. Due to the complexity of the deep-sea environment and the difficulty of the seabed operation, in-situ and high-precision deformation monitoring of terrain and shallow strata simultaneously are big challenges for existing observation methods. This paper describes the design and experimental research of a terrain and strata deformation monitoring system based on MEMS (Micro-electro mechanical system) sensor network (SN). The SN consists of a horizontal array and a vertical array containing multiple cascaded MEMS accelerometers. The pitch angle and roll angle of the monitoring node can be calculated through the three-axis components of the accelerometer in the gravity field. Then, a reconstruction model of the terrain and strata deformation was proposed based on the rotation matrix and the arc model. To evaluate the monitoring system and validate the reconstruction model, a field experiment was conducted on a tidal flat in Changzhi Island for one week. The deformation of the terrain and strata and the pore water pressure were measured and obtained. The results demonstrate the feasibility of the proposed system.