Not all earthquakes move the soul: Diane Browne, A Tumbling World...A Time of Fire (Jamaica: Arawak, 2002).
Thank you to Nalo Hopkinson for bringing this one back from Jamaica for me. It isn't very good, but always helpful to reach beyond imperialist shores.
Vanessa and Kerry get sent to their aunt and uncle for the vacation-a punishment for poor grades. Uncle sends them back into the past in his Time Mill.
Annoyingly, the machine covers space as well as time so they end up in Kingston. They have encounters with people, work out they are in 1907 and eventually experience the earthquake of the period. The whole thing feels like a Disney experience. Browne has a number of social issues she wants her readers to recognise, but hair straightening seems the most important (social and class divisions are described, but not processed by either author or protagonists). And beyond all of this, the "pay off", the experience of the earthquake, just doesn't work--it's limp.
I don't think this book is flawed because it's poor sf, it's just an aimless book. The time travel is there to give a history lesson and inspire children with an interest in the past but it is all just too obvious.