[Geysers] Trip report 15-17 July

[Gordon Bower]

Warning: limited geyser content. Most my time this trip was spent in non-geyser portions of the park.  I was briefly at Norris on the 15th, and briefly in the southern basins on the 17th.

At Mammoth on the 15th I can confirm the facebook report that New Highland Terrace is active again (not the whole thing, yet anyway, but one nice swath of orange with water disappearing into the 1970s rubble halfway down the side). There is one drinking-fountain-sized bubbler on Narrow Gauge visible from the road (and from the lower terraces / Village area if you have REALLY sharp eyes), and a lot more on the back side accessible from the old Howard Eaton trail. 

I haven't seen anyone follow up on the alleged eruption of Ledge that was mentioned secondhand on the list a week ago. I wouldn't rule out the possibility of it. The area has changed significantly from 2 months ago anyway. The (former) pressure pool which has been choked with green scum and quietly overflowing every time I've seen it recently is now choked with orange scum and about a goot below overflow. The steam vent between Ledge and Guardian is spitting out a lot of water -- more like the last 15 seconds of Lion or Beehive than 'just' a steam vent. A new runoff channel from it carries a steady stream of water down the hillside between Ledge's main vent and the 'finger' vents. Some of the water pours into the main vent, the rest goes down Ledge's runoff channel. I have no strong opinion about whether the area on the flats below has been rearranged enough to require a full-sized Ledge eruption to explain it. A smaller eruption from Ledge, or a misidentification of a remarkably water-charged episode from the steam vent by someone who hadn't ever seen the real Ledge, are also possible. (I have never been happy with calling it the Black Growler, even if it appeared the same time the original Black Growler went quiet.)

There is more water in Porcelain Basin now than there was in May. Water is again pouring into Splutter Pot. I also saw three other things in Porcelain that I don't remember ever seening before: 1. A new-to-me geyser directly in line with an imaginary continuation of the boardwalk beyond Pinwheel. The water in a heavily iron-stained pool domed up, only a few feet high but very wide, every few minutes, the whole hour I was there. Sometimes just once, other times three or more times in a row. 2. Constant boiled but failed to erupt, 1721-1723 and 1738, before succeeding in having a single eruption at 1754. It struck me as a larger than usual eruption; my impression from the overlook was "larger than Plume." 3. The longest and largest eruption of Fireball I've ever seen. It started shortly between 1715 and 1719 (I was briefly out of sight of it while looking at Ledge), and for the first several minutes looked as large or a little larger than Aurum. It died down to its normal size, and then waxed and waned several times between 1738 and when I left the area at 1807, fooling me into thinking it was about to stop. It filled the channel all the way to the boardwalk by about 1740.

Also at Norris: a 5-minute eruption of Arsenic at 1725; Porkchop full and milky at 1650; Pearl milky and overflowing the first time I walked past, but also thumbing and gently bubbling, Doublet Pool style, at 1654. We waited a few minutes but didn't see a splash. Rubble has kept its crater clear of debris and rearranged the rocks in its runoff channel some more since May but it wasn't steaming or overflowing. Monarch was quiet when I walked down (~1646) but boiling hard from both vents at 1702. I didn't walk the portion of the trail from Porkchop around to Echinus and Steamboat.

I don't know whether the YVO thermometer on Constant is able to resolve single vs. double eruptions a couple minutes apart, or whether it reliably detects boiling episodes that don't lead to an eruption. (I suspect not.) A look at the online daily and weekly graphs implies the 'normal' activity is an eruption every 30 minutes or so, sometimes preceded by enough preplay to cause a small increase in temperature, but that there have been a number of episodes several hours long without sharp eruption spikes. Those of you who watch the YVO page might also be curious about the way Steamboat seems to reliably 'take a break' about once every 6 days.

Elsewhere in the park: at Mud Volcano on the 17th, the Dragon's Mouth is louder and discharging more water than it did in 2004 or 2009, though still a far cry from what it was doing when I was a kid. Churning Caldron was going strong; some new sizzling areas around the south side of Mud Geyser. No new holes in the parking lot. The mud cone across the river was standing tall and steaming hard but not throwing any visible mud.

Le Hardy Rapids is higher than I've ever seen it. (And an incredible number of moths in the air!) The trail along the riverbank is still open but the boardwalk is hanging over the water and becoming wobbly in several places. There is still a lakelike backup of water into all the creeks passing under the highway in Hayden Valley. Lots of islands in the river with full-grown trees underwater. I am surprised there has been so little in the way of washed-away trees or erosion of cut banks. 

West Thumb is still closed. I don't know whether this is because of trails being underwater, or a leftover from the June elk calving. I seem to recall high-water springs in the past where the trail was barricaded at Black Pool and Lakeshore Geyser, but the rest of the basin was open. 

On my way out of the park on the 17th, I caught one Plume (1542), Till (1603IE), several Botryoidal intervals in the 4 1/2 to 5 minute range, and one 27-minute interval on A-0. Note the change from Memorial Day weekend when I had 10 intervals averaging 32m47s (range 30m58s to 35m01s) and Tara reported two of 31 minutes.

GRB