Last Known Eruption
59d 15h 48m ago

Latest Eruptions

Eruption DurationInterval
19 Sep 2019 @ 1314 ie>25m 49d 2h 48m
01 Aug 2019 @ 1026 ie14d 16h 21m
17 Jul 2019 @ 1805 ie7d 8h 18m
10 Jul 2019 @ 0947 ie51y 363d 17h 2m
24 Jul 1967 @ 1645

Interval Statistics

Interval Count4
Min7d 8h 18m
Max51y 363d 17h 2m
Mean13y 17d 11h 7m
Median31d 21h 34m

Latest Notes

Note IDStart Time (US/Mountain)End Time (US/Mountain)EntrantNote
13933 13 Oct 2019 @ 1550 --- cb Root pool is mostly clear, green in color, with occasional ball sized bubbles in the north pool. Both pools are connected with the water level ~10" below the high water mark on the stick in the channel. Tantalus is mostly clear, greenish, and barely in overflow with mild boil over the center (main) vent, the shoreline vent and the channel vent.
13926 12 Oct 2019 @ 1225 --- cb pool is fairly clear and greenish in color. (I can see the sand bar under water) water level is low but still in overflow. Very slight boil in the center & the west shoreline (channel) Root pools are high and the channel full. no bubbles or boil in either pool.
13889 05 Oct 2019 @ 1201 --- cb pool is in overflow and water is fairly clear and greenish in color. boiling in the center and in the overflow channel. Root pool both pools are clear and faintly green in color. north pool is 2' below the channel and has a vigorous boil. South pool is 1' below the channel with 3 areas with golf ball sized bubbles.
13844 30 Sep 2019 @ 1845 --- Ben VL Root pool is clearer than I've noted it all summer. Can actually see down in it, and the vents on the southern pool are easily visible. Water level around a foot below the topmost part of the land bridge.
13740 07 Sep 2019 @ 1432 --- Polly Calm pool
13390 25 Aug 2019 @ 0733 --- ypcaribou Full and bubbling in several spots. Too steamy to see color or clarity. Water in Tantalus Creek near Vixen had gray mud in it. Root pool empty except splashing deep in crater on left side.
13380 24 Aug 2019 @ 0939 --- MAB Maybe not Tantalus, but something upstream from the Vixen bridge. Tantalus Creek at the bridge was muddy at 0939, and less muddy but not clear at end of day.
13302 17 Aug 2019 @ 1713 --- cb Tantalus pool is relatively calm and clear compared to past observations. Only the center area has some small bubbles breaking the surface and sending out convection waves. color is grayish brown but clear at the bridge. No activity in the surrounding area of the pool. Root pools north pool is down 8' from the high water mark. it has a small pool of water in the bottom of the pool that has a vigorous boil. South root pool is empty but the mud is moist!
13255 14 Aug 2019 @ 1623 --- cb basicly pool is calm, has a small boil in the center of the pool. water under the bridge by Vixen is clear. ** Dishwater spring is clear, blue and slightly overflowing. ** Root pool's North pool has water in the bottom with a vigorous 1-2' boil. The South pool is empty.
13160 11 Aug 2019 @ 0830 --- RMichaels High and boiling muddy water up to a few inches.
13124 09 Aug 2019 @ 0816 --- cb Root pool water level is high again - 6" below high water mark on the east side of the north pool. North pool has a 4 point boil. Channel is completely covered with water and both pools are again connected and at the same level. water is a cloudy clay color. Tantalus is the ever changing feature! Today the main pool is mostly calm, 4" lower, with a few areas that have very low bubbles breaking the surface. However, On the NE side, 2' away from the runoff channel, there are 2 pools that are constantly and vigorously boiling, throwing water 1' - 1.5'. Dishwater spring is in overflow again.
13088 07 Aug 2019 @ 0750 --- bbev Very steamy, appears full. could not see or hear anything due to heavy steam.
13076 06 Aug 2019 @ 1730 --- cb Tantalus is flat and mostly calm. 2 small areas with bubbles. Root pools north pool is about 4' below high water mark with a vigorous 1' boil, south pool was mostly empty with a small pool of water in the base ~ 2' in diameter.
13016 04 Aug 2019 @ 0752 --- cb Root pool, south pool is empty and the north pool has water low in the crater with a vigorous boil to ~ 8". Tantalus is 1' below the high water mark with a light boil in the center.
12994 03 Aug 2019 @ 0825 --- cb Root pool water level is at the channel and is on the rise. Tantalus pool is high and very steamy. Low level bubblers, 1 - 2", in the same areas of the pool as previous days. ** @ 1300 Root pool structure changed at some point between this mornings observation and 1300. A large clump of soil and debris sluffed off the north pool channel, clogging the channel and changing how the 2 pools exchange water. @1300 Tantalus is one large pool with 1 large boil in the center. water level is high. color is similar to dark chocolate.
12961 02 Aug 2019 @ 1723 --- cb arrived this afternoon to find Root pool down to below the channel but appears to be filling. Found Tantalus about 1.5 - 2' below the rim of the pool. Did something big! No obvious sign of an eruption: no splatter spray marks or debris. It is filling from Tantalus creek with multiple boiling areas in the main pool and one in the south runoff channel. I find this fascinating!
12957 02 Aug 2019 @ 1201 --- cb root poot is draining out. pool to the north water level is down 5' from high water mark with a roiling boil. south pool is empty. Tantalus is the every changing feature. This afternoon it is erupting in what looks like a crack or fisure in the south runoff channel. small boil in the center where yesterday it was the HUGE boil. Another small boil toward the east. pool is high and thick chocolaty brown in appearance. There is a 3' in diameter yellow sulfurous pool on the north end of Tantalus pool that is steaming and had some runoff into Tantalus. The putrid smell is back!
12950 02 Aug 2019 @ 0801 --- bbev Difficult to see in dense geyser fog, but appears quiet and flat in a fairly high pool. May be some boil in center. Root pool gently boiling at north end ~10" below high water mark.
12931 01 Aug 2019 @ 1751 --- bbev Gently boiling in center and eastside of a high pool. Root pool separated and boiling ~40" below high water mark.
12923 01 Aug 2019 @ 1026 --- cb Root pool is completely drained/empty! I can hear at boiling low in the crater. Tantalus is to 2' - 4' and is VIGOROUSLY BOILING the entire width of the pool in 2 areas. Tantalus is a very muddy, brown black, roiling pool! hum. . . ! Tantalus Creek at the bridge is a thick, dark brown/black, muddy creek. zero clarity.
12900 31 Jul 2019 @ 1626 --- cb this afternoons observation has Root pool high with vigorous boil in both pools and Tantalus low with many areas of roiling muddy brown boiling. areas are in the main one in the middle of the pool, 1 on the edge toward Crater Spring, 2 + 1 small, very low almost mud pot*ish (drier area) on the NE edge and 2 in each of the runoff channels toward the bridge. whew. The longer i watch, the more small bubblers i see!
12888 31 Jul 2019 @ 0841 --- cb Root pool us low. water just barely in the channel between the 2 pools. moderate boil in both pools. light green in color. Tantalus is more active. 3 main areas with a vigorous roiling wide boil that bloops to 5" in height. muddy brown in color. Runoff water at the bridge is a muddy brown color.
12840 28 Jul 2019 @ 0732 28 Jul 2019 @ 0745 ypcaribou Full, calm with some tiny bubbles. Hard to see with steam but looked a bit brown.
12808 26 Jul 2019 @ 1021 --- cb Tantalus pool is low. Has 2 areas within the pool, 1 is a light murky green color and the other is a muddy brown. It is mostly a calm flat pool with 5 very small areas that have bubblers. The inflow stream has 2 frying pan springs and 3 areas with small geyser features that reach heights of 3 - 5". Root pool is low, calm and a muddy green in color. no areas that have a boil just a few small bubbles. No putrid smell today!
12797 25 Jul 2019 @ 1645 --- cb low pool. water appears clearer than last observed. greenish yellowy (? weird) in color. 2 areas with bubbles not a boil.
12568 23 Jul 2019 @ 1120 --- cb Pool is low, light brown in color and really calm. It has 2 areas with a minimal (2") boil. Root pool as a weak boil on the south end and is filling.
12546 20 Jul 2019 @ 1332 --- cb much like yesterday except pool is lower. 2 main boiling areas that are only inches high. A dozen or so bubblers in a variety of areas within the main pool. color is opalescent/milky green. (water at the bridge is clear) Root pool is low, (but coming up) it is just above the channel between the 2 pools. it is a murky yellow/green color. putrid smell is barely detectable.
12535 20 Jul 2019 @ 0812 --- bbev 2D, 2hrs post SB: pool appears low and flat as observed from steerage.
12530 19 Jul 2019 @ 1708 --- cb both Root and Tantalus are pretty much the same as this morning except the pools are clearer and a lighter shade of green.
12524 19 Jul 2019 @ 1035 --- cb pool is low with 15+ small bubblers and 4 areas with significant boiling. The boil on the south end is a roiling boil to 5". pool color is a light brownish green color. Root pool is on the fill with a 2 point rolling boil on the north end with small bubblers on the west end. color is also greenish brown. It has a slight odor today but not as pungent as it has been this past few weeks.
12502 17 Jul 2019 @ 0750 --- bbev Tantalus has slight increase in boil from last evening, relatively clear, in low pool.
12503 16 Jul 2019 @ 0815 16 Jul 2019 @ 1830 bbev Remained flat, with light boil, low pool, for most of the day as observed from steerage.
12514 15 Jul 2019 @ 1800 15 Jul 2019 @ 2115 bbev Tantalus mostly flat, with low water level, light boil at south end of pool.
12441 11 Jul 2019 @ 1615 --- cb calm and pool is high. 2 spots with a 2" boil. water is clearer than yesterday not brackish & muddy.
12396 07 Jul 2019 @ 0932 --- cb pool is high again and water is clearer. The mud pot in the south end of the pool is again spouting white water insteady of muddy brackish water.
12111 04 Jul 2019 @ 0850 --- Ben VL Tantalus is no longer acting as a mudpot like it was yesterday. The pool is quiet. I observed a small hole immediately east of tantalus after yesterday's 1726 SB push that was bubbling clear water to a couple inches. That hole has since enlarged and is now sitting inside a small crater with a raised edge. It is now perpetually blooping mud or muddy water to a few inches, accompanied by a steam locomotive chugging noise.
12096 03 Jul 2019 @ 1000 --- cb water level in the pool is MUCH lower and has morphed into a black/gray sputtering mud pot splashing 1' in height from 2 vents. water in Tantalus Creek at the bridge is clear again.
12023 29 Jun 2019 @ 0815 29 Jun 2019 @ 1230 cb Tantalus spring is calm and no longer erupting. root pool is refilling and the "land bridge" connecting the 2 sides of the pool now has a water channel connecting the 2. The icky H2S smell that permeated this area for the past 3 days has greatly diminished! **1230 > Tantalus has one small boil (2 - 3") on the edge closest to the walkway and the water color is not so muddy brown as the last 2 days. On the Northern edge of the pool there are 2 areas that have sizzling blippy mud features in addition to a sulfurous yellow sizzler about 5' N of the pool and in a runoff channel that was first observed yesterday by TC.
12005 28 Jun 2019 @ 0745 28 Jun 2019 @ 1015 ypcaribou As seen from boardwalk nearest Tantalus Geyser, it was spouting/splashing dark, muddy water ftom two spots in muddy spring continuously. Lovely aroma wafted my way while I sat nearby watching Steamboat minor play. CB told me she saw it doing muddy splashes on 6-27-19 too. Tantalus Creek water muddy at bridge near Vixen. Collected gray mud at edges and high spots in creek.
12024 26 Jun 2019 @ 1730 --- cb Noticed Tantalus Creek was a murky, muddy brown color at the bridge. He walked up toward Echinus to find out the origin of the color change and found Tantalus a muddy brown roiling pool with 3 areas that were erupting. 1 area to height of 3'.
4996 21 Sep 1979 @ 1800 --- research-mab 09/21/1979 Disturbance “Decker Geyser” increase in activity, erupting 1 to 3 feet with muddy gray water. Bubble brigades of this summer are gone.
5242 07 Sep 1976 @ 1800 --- research-mab 09/07/1976 Decker Geyser has several actively boiling spots and an active crack vent at the SW edge that is noisily splashing muddy water 4’ high.
7378 27 Oct 1967 @ 1800 --- research-mab 10/27/1967 Decker – full, quiet and clear green. Activity north of the geyser has virtually died out.
7367 27 Sep 1967 @ 1800 --- research-mab 09/27/1967 Decker and Root – quiet and full. Virtually all the activity north of Decker has quit.
7364 20 Sep 1967 @ 0800 20 Sep 1967 @ 1615 research-mab 09/20/1967 Decker Geyser and Root Spring are both drained this morning. Decker was drained down 2½ feet but showed no signs of an eruption. Water from Echinus raised the level about 2 or 3 inches. This leaves several questions, 1) when did the drain down occur? 2) How far down had it drained? 3) was there an eruption someplace? Decker filled again at 4:15 pm.
7354 18 Sep 1967 @ 1800 --- research-mab 09/18/1967 Decker Geyser – quiet – no new activity on north side for over two weeks.
7327 11 Sep 1967 @ 1800 --- research-mab 09/11/1967 Decker – steam vents have quit. Much of the activity has quieted down on the north side of the pool.
7325 30 Aug 1967 @ 1800 --- research-mab 08/30/1967 Decker Steam Vent still active. Can be heard from Echinus and Cistern.
7323 29 Aug 1967 @ 1800 --- research-mab 08/29/1967 A new and powerful steam vent has opened on the north side of Decker Geyser. It can be heard from the lower stage at Steamboat while the big one is quiet. Steam is jetting under high pressure from a crack 2 ft long and ¼ inch wide. Temp 202º
7318 23 Aug 1967 @ 1800 --- research-mab 08/23/1967 Root Spring and the two green pools west of Arch Steam Vent have drained down about 4 inches. All are still green – no sign of eruption in these or at Decker Geyser.
7312 08 Aug 1967 @ 1300 --- research-mab 08/08/1967 Decker Geyser – rift vent was playing 1 ft high at 1pm.
7311 03 Aug 1967 @ 1200 03 Aug 1967 @ 1500 research-mab 08/03/1967 R.H. vent at the new geyser played during afternoon. About 3:00 the water level of the pool dropped and the activity ceased.
7289 30 Jul 1967 @ 1800 --- research-mab 07/30/1967 Decker Geyser began boiling water to a height of 1½ ft from a new vent near the rift vent. This is a rift about 4 ft long following the curve of the pool. It is in the same position as a small vent that developed during the first eruption but never amounted to much.
7291 30 Jul 1967 @ 1100 30 Jul 1967 @ 1525 research-mab 07/30/1967 Boiling activity of new vent of Decker Geyser started about 11:00 and ceased a little after 3:10. Water level in the pool began to drop, it fell 5 or 6 inches as activity ceased. Then vent in the middle of the pool began to boil vigorously and the water level rose at 3:18. By 3:25 the pool was almost full; activity was high. Then Echinus dumped into it and cooled it down. The temperature of the new vent was 200º At the same time Echinus measured only 184º about five minutes before an eruption.
7287 28 Jul 1967 @ 1245 --- research-mab 07/28/1967 Decker Geyser was boiling some water on the south side some 12 to 14” at 12:45
7301 27 Jul 1967 @ 0800 --- research-mab 07/27/1967 New Geyser (Decker Geyser) 138º this am, No further excitement.
7308 26 Jul 1967 @ 0800 --- research-mab 07/26/1967 The new geyser is discharging a little gas from the main vent. Aside from that, all is quiet down there. I’d like to propose the geyser be named for Mrs. Decker – perhaps “Mrs Decker’s Geyser” or “Decker’s Geyser” Temperature in main vent 135ºF
7259 25 Jul 1967 @ 1535 --- research-mab 07/25/1967 New Geyser began boiling again over the main vent at 3:35 pm.
7286 25 Jul 1967 @ 1300 --- research-mab 07/25/1967 At 1:00 July 25 the pool was full and clearing with no action (no unusual activity) to be seen. (See more complete report appended to back of this book or on file in Norris Records.)
7285 25 Jul 1967 @ 0630 --- research-mab 07/25/1967 New Geyser refilled after having drained down 2 feet at 6:30 am.
No attachments for this geyser.
Baseline does not exist.


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