A recent study found that an especially massive tropical volcanic eruption in 1257, possibly of the now-extinct Mount Samalas near Mount Rinjani, both in Lombok, Indonesia, followed by three smaller eruptions in 1268, 1275, and 1284, did not allow the climate to recover. That may have caused the initial cooling, and the 1452–1453 eruption of Kuwae in Vanuatu triggered a second pulse of cooling. The cold summers can be maintained by sea-ice/ocean feedbacks long after volcanic aerosols are removed.