Final answer:
Valparaíso experiences larger magnitude earthquakes due to its location at the juncture of tectonic plates, similar to Tokyo on the Philippine plate, which has a history of significant seismic activity.
Step-by-step explanation:
The city that experiences larger magnitude earthquakes between Helena and Valparaíso is Valparaíso. This is due to the active seismic forces resulting from the juncture of tectonic plates near the region. Valparaíso is comparable to Tokyo, situated at the opposite end of the Philippine plate.
This plate is often subject to many earthquakes, some of which could be as many as 20 per day. Although some earthquakes are too weak to be noticed, the region has experienced significant seismic events, such as the 1990 Luzon earthquake with a magnitude of 7.8, which resulted in over 1,621 deaths and extensive infrastructure damage.