The Slungawarning algorithm is based on watching seismicity of small earthquakes as well as of their source dimensions. The idea behind this is that the minimum size of source radius of earthquakes (microearthquakes) varies in time and space in the faulting area. A special case is the preparatory period of large earthquakes. Observations in hindsight of earthquake activity since 1991, after the start of the SIL system, by this algorithm provide short-term alarms for the larger events with few false alarms. This algorithm is now applied routinely for testing and gradually for short-term warnings at IMOR.DG. The method has been developed at UUPP.DGEO (see Subproject 2).