  In this paper we study the energy of ULF electromagnetic waves that have been
recorded by the satellite DEMETER, during its passing over Haiti before and
after a destructive earthquake. This earthquake occurred on 12/1/2010, at
geographic Latitude 18.46o and Longitude 287.47o, with Magnitude 7.0 R.
Specifically, we are focusing on the variations of energy of Ez-electric field
component concerning a time period of 100 days before and 50 days after the
strong earthquake. In order to study these variations, we developed a novel
method that can be divided in two stages: first we filter the signal keeping
only the very low frequencies and afterwards we eliminate its trend using
techniques of Singular Spectrum Analysis, combined with a third-degree
polynomial filter. As it is shown, a significant increase in energy is observed
for the time interval of 30 days before the strong earthquake. This result
clearly indicates that the change in the energy of ULF electromagnetic waves
could be related to strong precursory earthquake phenomena. Moreover, changes
in energy were also observed 25 days after the strong earthquake associated
with strong aftershock activity. Finally, we present results concerning the
comparison in changes in Energy during night and day passes of the satellite
over Haiti, which showed differences in the mean energy values, but similar
results as far as the rate of energy change is concerned.
