yea i know what you mean . i have a just turned 2yr old who was a bit young to notice the sept one , and feb one but since June she gets very jumpy everytime theres an aftershock and screams for me everytime , altho she is still a good sleeper . Its really hard on the little ones aye , esspecially because you cant talk to them about it .
Im sorry i wasnt much help . Hope you get some asnwers tho . perhaps go to your local GP , im sure its happening alot and he/she may have some calming techniques or suggestions for you to try , also maybe visit a health shop and see if there are any natural remedys you can use on toddlers for calming them down a bit at night time .