There were several hundred quakes centered beneath the north end of Yellowstone Lake during the period, with the strongest registering a magnitude 3.9 on Saturday, January 3.
Only a few people actually felt the shaking since most of the park is only accessible by snowmobile at this time of year.
“What's interesting about this earthquake swarm is that it's in a very large and active volcano,” geologist Robert Clayton told KIFI television.
Yellowstone lies mostly in northwestern Wyoming and is within the caldera of a volcano that last erupted 70,000 years ago. Clayton said he believes the shaking was caused by heat and steam, created by deep magma, escaping through the cracks in the Earth’s crust.
The last time such a swarm of seismic events occurred in Yellowstone was over a three-month period in 1985.