originally posted by: Hillbilly123069
With the 4.4 depth on that recent quake this morning, does that mean the cauldera is getting wider?
The ground deformation occurring in north-central Yellowstone abruptly changed direction on about April 6, 2014, one week following a M4.8 earthquake in the same region. The change is most prominent on the NRWY GPS station (earthquake.usgs.gov...), but is also detectable on other nearby stations. Since April 6, 2014, NRWY has moved about 0.5 cm west, 1 cm north, and 2 cm down, reversing about 1/3 of the deformation accumulated over the previous 8 months. (Note that last month’s update erroneously reported that NRWY had moved 2 cm north since August 1, 2013. In fact it had moved 2 cm SOUTH).
Slow caldera uplift, which began in early 2014 after 4 years of subsidence, continues at about 2 cm/yr.
3.2 2014/06/03 03:52:52 44.780N 110.764W 9.1 29 km (18 mi) S of Gardiner, MT
1.9 2014/06/03 03:52:31 44.807N 110.748W -3.4 26 km (16 mi) S of Gardiner, MT
2.7 2014/06/03 03:39:25 44.788N 110.760W 8.6 28 km (17 mi) S of Gardiner, MT
3.5 2014/06/03 03:33:27 44.807N 110.760W 20.2 26 km (16 mi) S of Gardiner, MT
A north-south trending series of earthquakes, over seven miles in length, which began in September, 2013 picked up again from May 10 to 31 with 42 events. The largest earthquake was magnitude 3.5 on May 31, at 4:25 PM MDT, located about 13 miles southwest of Mammoth, Yellowstone National Park.
Earthquake sequences like these are common and account for roughly 50% of the total seismicity in the Yellowstone region.
Subsidence in north-central Yellowstone continues, although the deformation rate has slowed.
Uplift within the Yellowstone Caldera, which began in 2014 after 4 years of subsidence, continues. Since the beginning of 2014, the caldera has risen about 2 cm.
Analysis of the data reveals that the magma reservoir contains between about 5 and 15% molten rock (melt) that occupies pore spaces between solid (crystalline) material. Magma typically does not erupt unless it has greater than 50% melt.
The larger imaged size of the magma reservoir better matches the geologic record of Late Quaternary volcanic eruptions and lava flows but, importantly, does not increase the volcanic hazard in the Yellowstone region.
North of the prolific Old Faithful, and across the Firehole River, sits the geyser know as Giantess. You’ve probably never heard of the Giantess because for the last 2 years and 139 days – until January 29, 2014 that is – the geyser was dormant. So imagine the National Park Service’s surprise when on the 29th this very large and very noisy geyser erupted and stayed active for over 40 hours.