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WEST YELLOWSTONE, Mont. (AP)-- Yellowstone National Park absorbed without damage or harm to humans on Monday the most severe earthquake since a killer quake of 1959.
The 1959 earthquake killed 19 persons and dammed the Madison River into a new body of water now called Quake Lake. The 1959 tragedy measured 7.1 on the Richter Scale while the National Earthquake Information Center of Golden, Colo., put the strength of Monday's quake at 6.0.
The focal points of earth movement, called epicenters, of the two earthquakes were in the same general area, a portion of southern Montana just to the northwest of Yellowstone's border.
Acting Yellowstone Supt. Robert Haraden said crews worked Monday night to clear one park road that was closed when the earthquake shook down boulders in the fragile beauty of the country between Norris and Madison Junction.
Haraden said all Yellowstone campgrounds and facilities remained open.
Earth movement is constant at Yellowstone. Haraden noted that a small seismograph stationed at the visitor center near the Old Faithful geyser has recorded more than 2,000 earth movements so far this year.
Most are so tiny that humans cannot feel them but Monday's earthquake rumbled with a force that shook buildings and rattled windows 200 miles away. Citizens in Great Falls and Billings reported feeling the earthquake.
Telephone service was temporarily knocked out at Madison, Old Faithful and West Yellowstone for a time.
[Deseret News; July 1, 1975]
WEST YELLOWSTONE, Mont. (AP)--A series of earth tremors struck the Yellowstone National Park area Monday afternoon, with an early shock felt 100 miles north and more than 220 miles east of the park.
Yellowstone was the scene of one of North America's strongest recorded quakes (7.1 on the Richter Scale) in 1959, when mountains toppled to form a new lake on the Madison River.
A source in Livingston, Mont., said the first tremor hit at 12:47 p.m. Other tremors were recorded at 1:05 p.m. and 1:22 p.m.
An earthquake measurement device at the University of Utah measured the intensity at 5.5 to 6 on the Richter Scale. The University of Nevada recorded the tremor at 6.25.
A University of Nevada spokesman said the earthquake's epicenter was located 575 miles northeast of Reno.
[Salt Lake Tribune; July 1, 1975]
By Associated Press
A moderately strong earthquake shook parts of Yellowstone National Park in Wyoming Thursday, 13 hours after another quake rumbled through the seabed 350 miles off the coast of Oregon.
There were no reports of damage from either quake, and there was no indication they were related.
Waverly Person, chief geophysicist at the National Earthquake Information Service of the U.S. Geological Survey, said residents of Mammoth, Wyo., reported feeling the Yellowstone tremor, which registered 5.0 on the Richter scale of earthquake magnitude.
Person said the quake at 3:36 p.m. local time--5:56 p.m. EST--was about one minute after a smaller quake struck in the area. The epicenter was in the northwestern corner of the park.
The quake was in the same general area as a tremor on June 30, 1975, which measured 6.0 on the Richter scale and caused minor damage. But Person said he expects no damage this time because it is not the tourist season and few other people live nearby.
Similarly, the predawn earthquake measuring 5.7 on the Richter scale occurred 350 miles off the central Oregon coast caused no damage. It was recorded at about 1:51 a.m. PST.
[Salt Lake Tribune; December 10, 1976]
WEST YELLOWSTONE, MONT. (UPI)-- Yellowstone, oldest and largest of the nation's national parks, was shaken by a series of earthquakes Monday, triggering landslides that blocked one of its major roads.
The strongest earth tremor hit 6.2 on the Richter scale and rocked a large area of the Northern Rockies shortly before 1 p.m. Its epicenter was put in the Gallatin National Forest, about 50 miles from the center of the devastating 1959 quake near Hebgen Lake that left more than two dozen dead and caused flooding and earthslides.
Monday's quakes were felt over a broad area of Montana with reports coming in from Great Falls, Bozeman and Billings. But no damage was reported in those areas.
In Yellowstone Park, a major road between Norris and Madison Junctions in the west-central part of the park was blocked by a landslide, but the road was expected to be open today.
Joe Carder of the Park Service was eating lunch when Monday's most severe temblor struck.
"The whole floor started quivering," he said. "There wasn't any noise; no dishes rattled. There was just a gentle rolling of the floor.
"I knew right away what it was. There are no freight trains going through here."
A policeman in the small city of West Yellowstone on the park's rim said it was "a little shaky" there, but he added that there was no damage and the residents seemed to be taking the quake in stride.
The University of California seismographic station at Berkeley timed the most severe quake at 12:56 p.m. Yellowstone time and a spokesman said "there were a whole swarm of quakes. That was the strongest."
Earthquakes with a Richter value of 7 or more are commonly considered major in magnitude. The Richter Scale has no fixed maximum or minimum; observations have placed the largest recorded earthquakes in the world at 8.8 or 8.9 level, but Richter numbers are not used to estimate damage, just intensity.
[Wyoming State Tribune; July 1, 1975]
MAMMOTH SPRINGS JUNCTION (UPI)-- Officials say the largest earthquake in a year and a half has been recorded in a remote area of Yellowstone National Park, but there was no damage.
The National Earthquake Information Service at Golden, Colo., said the quake Thursday registered 5.0 on the Richter scale. Buildings shook but no damage was reported, Bob Haraden, assistant park superintendent, said.
The epicenter of the quake was in the remote central area of the park, between Norris Junction and Canyon Junction, Haraden said.
"It felt rather obvious here at Mammoth," said Bob Haraden, park assistant superintendent. "The building shook. It was larger than most but there are earthquakes recorded here every day."
The quake was the largest since a six-magnitude tremor struck June 30, 1975, the NPIS said.
Haraden said there were three shocks associated with the quake. The first hit at 3:30 p.m., the next five minutes later, and the last, which was the most severe, a minute later, he said.
Haraden said his office received no calls from curious persons. Few persons are in the park because all but one road is closed for the winter, and the snowmobile season has not yet started.
Haraden said earthquakes of lower magnitude are recorded daily in the park. He said tremors only occasionally are noticed.
The assistant superintendent said he felt any physical damage to the terrain in the park "would be limited to rockslides at the most."
"We haven't sent any people out where it happened, but someone probably will be passing through the area in the next day or two and will make some observations," he said.
Haraden said there was a possibility that the quake could affect thermal activity within the park.
"We've had several hundred earthquakes this year, most of them you don't feel," he said. But they account for constant change in thermal activity at the park. The thermal features are just not fixed."
He said a specialist may be summoned to determine whether there have been any significant changes in the thermal features in the vicinity of the quake.
[Wyoming State Tribune; December 10, 1976]
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