In recent years, the widespread use of social media has facilitated the propagation of messages after disasters. Unfortunately, because the veracity of messages is often difficult to determine in a disaster situation, social media also facilitates the rapid diffusion of rumors. Current studies have examined why individuals post or transmit rumors on social media. However, investigating factors affecting the initial rumor transmission is just the first step for rumor control after disasters. After rumors have been transmitted, understanding what accounts for message retransmission in disasters is especially vital. To address this gap, we develop a model of rumor retransmission on social media during disasters based on rumor theory and the elaboration likelihood model. We also discuss the differences between our model and the model of rumor transmission. We believe that our model can contribute to research on social media use in disasters, and the practice of disaster management.