LAVA FLOW TRAIL
STOP 11
Dating the eruption
 |
 How
can we find out when Sunset Crater erupted? One way is to ask
a tree. Each year, a living tree adds a new layer of wood in a
ring around the trunk. The better the growing conditions, the
wider the ring. In times of drought, climate change, or disturbance
- fire, flood, or a volcanic eruption - little tree growth takes
place, and rings are very narrow.
|
We can count the
number of tree rings to learn the age of a tree. And we can compare
patterns of wide and narrow rings in different trees and stumps to learn
the actual dates they grew. This process is called dendrochronology.
To find trees
that grew at the time of the Sunset Crater eruption, scientists looked
at Wupatki, about 20 miles away. Wupatki Pueblo was a thriving community
after the eruption. Roof beams used in some of its rooms revealed several
narrow, dark rings, indicating a period of stunted growth in the years
1064 and 1065. Perhaps there was a severe drought or other disturbance
during these years, or those narrow rings may indicate volcanic activity
at Sunset Crater.
As new dating
technologies become available, we may learn more about the timing of
this eruption and others in the vicinity.
|
