Poland is in an intraplate area characterized almost everywhere by low recent tectonic activity. This does not imply, however, that earthquakes have not affected it, even in the – geologically speaking – recent geological past. This is due to Pleistocene glaciations, which left traces in the form of earthquake-induced deformed layers. The strongly deformed layers (seismites) as well as some fault zones with significant offsets crossing also Quaternary sediments can indicate fault (re-)activation due to glacial isostatic adjustment. We inventory and describe the five sites/areas in the intraplate northern and central parts of Poland where traces of glacial isostatic adjustment occur. We do not deal, however, with the mountain areas of southern Poland, because Alpine pressure and glacial isostatic adjustment may each, possibly jointly, have acted there as a trigger; distinguishing between traces left by them is not yet viable.

This chapter gives an overview of the use of soft-sediment deformation structures (SSDS) as palaeoearthquake indicators in formerly glaciated and periglacial areas. We review the most important processes of soft-sediment deformation and the different nomenclature used in the scientific communities.

So-called seismites are beds with SSDS that formed because of seismic shaking. However, in regions that were affected by glacial and periglacial processes, the use of SSDS as palaeoearthquake indicator is challenging and interpretation must be done with care. Earthquakes are only one trigger process of many that can cause liquefaction and/or fluidization of sediments, leading to the formation of SSDS. Ice-sheet loading, glaciotectonism and freeze and thaw processes in glacial and periglacial environments are also potential trigger processes that can cause the formation of similar types of SSDS, which can be easily mistaken for seismites. Therefore, we provide clear criteria to recognize seismites in the field. The combination of deformation bands that occur in the vicinity of basement faults with carefully evaluated SSDS is a robust indicator for palaeoearthquakes.

Fluidization represents an important particulate and multiphase operation, featuring dynamic interactions between a continuum fluid and a discrete phase. It is typically realized in a vertical column or pipe. Various fluidization regimes occur, depending on the property of the fluidizing particles, flow rate, and external field force applied. This chapter describes gas–solid fluidization represented by dense-phase fluidized beds and circulating fluidized beds. Fluidization under the gas–liquid–solid flow conditions is also illustrated with the inclusion of its limiting condition of two-phase flows. Basic topics of fluidization include the fluidization regime classification and characteristics, phase-interaction mechanisms in the dense and dilute phase fluidization as well as nanoparticle fluidization, fluidized bed systems, and multiscaled transport phenomena, such as clustering, agglomeration, breakup, and coalescence of dispersed particles or bubbles. For the numerical modeling of fluidization systems, the Eulerian–Eulerian modeling is extensively used and often coupled with the DEM models or kinetic theory models for collision-induced transport in the dispersed phase.