Novel solutions, which can include devices, systems, methods, than can measure earthquakes and other displacement events. Some solutions feature the integration of real-time, high-rate global navigation satellite system (“GNSS”) displacement information with acceleration and/or velocity data within a single device to create very high-rate displacement records. The mating of these two instruments allows the creation of a new, very high-rate displacement measurement device that has the full-scale displacement characteristics of GNSS and high-precision dynamic motions of seismic technologies. Such a device can be used for earthquake early warning studies and other mission critical applications, such as volcano monitoring, building, bridge and dam monitoring systems.