Interplanetary shocks are one of the crucial dynamic processes in the
Heliosphere. They accelerate particles into a high energy, generate plasma
waves, and could potentially trigger geomagnetic storms in the terrestrial
magnetosphere disturbing significantly our technological infrastructures. In
this study, two IP shock events are selected to study the temporal variations
of the shock parameters using magnetometer and ion plasma measurements of the
STEREO−A and B, the Wind, Cluster fleet, and the ACE spacecraft. The shock
normal vectors are determined using the minimum variance analysis (MVA) and the
magnetic coplanarity methods (CP). During the May 07 event, the shock
parameters and the shock normal direction are consistent. The shock surface
appears to be tilted almost the same degree as the Parker spiral, and the
driver could be a CIR. During the April 23 event, the shock parameters do not
change significantly except for the shock θBn​ angle, however, the
shape of the IP shock appears to be twisted along the transverse direction to
the Sun-Earth line as well. The driver of this rippled shock is SIRs/CIRs as
well. Being a fast-reverse shock caused this irregularity in shape