WhenOldFaithfulturnsfaithless

The loveliestearthquake detectorin California lives in the plainest ofplaces: a hole in the ground. Forfiveto55 minutes, youponderasmall rocky fracture — thensuddenly thrill to the spectacleof Calistoga’sOld Faithful Geyser, spoutingagraceful veilofsteamandhot water 20 to 80 feetinto the air.

Butif OldFaithful turns fickle —say,your waitdrags on an hour or more—there could be trouble brewing inits undergroundplumbingsystem. Hereinearthquake country,that’sneveragoodsign.

Such mysteries have long entrancedvisitorsofthis scenic little town at thenorth endofNapa Valley.TheWappoIndiansjourneyed here to ease achesand painsinits warm, mineral-rich waters. When businessman andpromoterSam Brannan arrivedin Calistoga inthe 1850s,he envisionedaSaratoga HotSpringsoftheWest.

Longbeforeit becamefamed for wine, theregion was known for such mysterious geology.“The wholeneighbourhoodof Mount Saint Helena isfullofsulphur and ofboiling springs, …and Calistoga itselfseems toreposeonamere filmaboveaboiling, subterranean lake,”marvelednovelist and poet Robert Louis Stevenson,in his book “The Silverado Squatters.”

Old Faithful traces its creationto that era,whenanill-fatedwelldriller inthe 1880shappened tostrike a deep magma-heatedreservoir.(But itseruptionsare all-natural,driven by escaped pressure initsunderground hydrothermalchambers. There are plenty of geysers inthe world, but only three—Yellowstone’sOld Faithful and thePohuto Geyser in NewZealand are the others —have the “Old Faithful” designation duetotheirregularity.)

Otherearthquake-detection systems relyontechnology,such as sensors to feelseismicwaves andcomputers to transmitdata to an “alertcenter” for messaging to phones. OldFaithful, in contrast, offers a vistaofMountSt. Helena andarugged,mile-long volcanic wall, Palisades. Overtime,the 6-acre park, beloved mostly for its roadside kitsch, fellinto disrepair. ButOld Faithful isin new hands. (Yes,you can buy a geyser.)

Tech-savvy owner KoraySanli, creatorof thetrip-planning Internet portalsDestination Intelligence, bought thepropertyin 2013 and hascommitted the sitetoscience.

Itnow features a small geology museum that describesnot only geysers,butother aspects of our roiling earth,such asearthquakes, volcanoesand tsunamis. It’s hungontoafew of itsBarnum &Bailey-likeoddities: Tennessee “fainting goats,” born withahereditarydisorderthat causes muscles to stiffen when startled, and Jacob four-horn sheep, whichsport horns out of the sides oftheir heads.

Butit’sthecreepystuffwe can’t seethatdeservesfull attention.Geologistsworryaboutstresses that cause deformation in the Earth’s crust, easing pressure inside the geyser’sreservoir and delaying the timebetween eruptions.

Research shows that Old Faithful’seruptions lengthened significantlyadayorsobefore threelargeearthquakes inNorthern California: the magnitude-7.1 LomaPrieta temblor in 1989, a 5.7 Orovillequakein 1975, and the 6.1 Morgan Hillquake in 1984.(It’snot perfect: Sometimes eruptions slow when earthquakes don’toccur.)

Ittook morethan an hour to eruptin August 2014—the day beforethe major 6.0 Napa quake —“soweknew itwas something strange,”Sanli told TVreporters.

WhenOldFaithful grows faithless,it’stime tocork thewine, fold up thepicnic blanketand head home.

At left: Calistoga’s Old Faithful usually spouts every five to 55 minutes, depending on the season.Center, clockwise fromtop: Luna Huckabee, of Los Angeles, feeds agoat; LeanneSkudrna, of San Francisco, andPaul Bartolotta, of Vallejo, watch an eruption;a dragonfly hovers above the water; the hillsbehind the attractionare bathedinsun andshadows.

BYTESACROSSTHEBAY