Dendrochronological Responses to the 24 October 1992 Tornado at Sunset Crater, Northern Arizona

This paper documents tree-ring responses to a historic tornado and re-evaluates prehistoric tree-ring changes seen in archaeological wood of Wupatki Ruin used to date the 11 century eruption of Sunset Crater. The historic tornado occurred at Sunset Crater, northern Arizona, on 24 October 1992, and trees within areas damaged by the tornado survived the event and continue living today. The objectives of this research were to document their ring-growth changes and to consider the possibility of tornado as a candidate disturbance agent for the prehistoric ring-growth changes of Wupatki. About half of the trees sampled within areas damaged by the tornado show one or more dendrochronological responses to that event, including ring-width release, reaction wood, ring-width suppression, and/or reduced latewood. Tornado damage is not a likely candidate for having caused the abrupt changes at A.D. 1064-65 seen at Wupatki. However, five living ponderosa pines at Sunset Crater experienced abrupt and severe suppressions in ring growth beginning decades ago and continuing today. No single disturbance agent seems obvious for causing these growth suppressions, but further research is merited to find the cause of these modern suppressions in order to propose a new candidate explanation for the A.D. 1064 suppression.