"The type of geologic process that created a soil deposit has a strong influence on its liquefaction susceptibility. Saturated soil deposits that have been created by sedimentation in rivers and lakes (fluvial or alluvial deposits), deposition of debris or eroded material (colluvial deposits), or deposits formed by wind action (aeolian deposits) can be very liquefaction susceptible. These processes sort particles into uniform grain sizes and deposit them in loose state which tend to densify when shaken by earthquakes. The tendency for densification leads to increasing pore water pressure and decreasing strength. Man-made soil deposits, particularly those created by the process of hydraulic filling, may also be susceptible to liquefaction."
from Department of Civil Engineering, University of Washington.
Nebraska has areas that fit some the geological criteria listed below. Nebraska does not have a significant risk of liquefaction resulting from an earthquake.
If you have more questions contact Mark Kuzila at 402-472-7537 or at mkuzila1@unl.edu