Physical or Chemical Change | 6 | |
Permafrost Change | 2 | |
Death / Die-off / Decline | 1 | |
Extreme Temperature | 1 | |
Seasonal Timing | 1 | |
Sinkhole / Crater | 1 | |
Ice / Snow Change | 1 |
3 | 1 | 2 |
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2 | 1 | 1 | 1 | 1 |
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SPRING | 3 | |
WINTER | 1 |
United States | 3 | |
Canada | 1 |