Earthquakes in California during 1864.
BY DR. JOHN B. TRASK.
Feb. 26th, 0 h. 40 m.—A light shock of earthquake at San Francisco. At 5 h. 45 m. a smart shock, having three distinct vibrations. On the day previous, an “Electric Storm” prevailed between Visalia, Tulare Co., and Los Angeles, which was very violent in its effects on the telegraph lines.
On the 27th, a heavy “Norther” commenced and continued till the eve of the 28th. This earthquake was felt at San José, fifty miles south, at the same hour, and was marked by two very smart shocks following each other in quick succession.
March 5th, 8 h. 49 m.—A smart shock of earthquake at San Francisco. The earthquake began at the above hour. The first wave was in a direction north and south, and lasted one and three-fourths seconds. Nearly one and a half seconds elapsed before the second shock, which occurred at forty-nine minutes, three seconds past eight o’clock, and had a duration of one and one-half seconds. The motion in this shock was rotatory.
Magnetism was not suspended in this nor either of the other shocks, this year. The total length of time included in this earthquake, was nearly 5 seconds. These observations were made at the height of 20 feet 4 inches above the ground, but persons situated at a greater height felt the vibrations longer and more severely.
We have brief details of this earthquake from Santa Rosa, at the north, to Santa Cruz at the south, and from Stockton at the east, for which we acknowledge our obligations to the Telegraph Company. At Santa Rosa it occurred at 8 h. 50 m. the shock was light. At Petaluma 8 h. 50 m., also light. At Stockton about 9 h., shock was severe. At Santa Clara 8 h. 40 m., the shocks were very severe. The church spires waved to and fro, and the earthquake is reported to have continued over two minutes, with light vibrations between the heavier waves. At Santa Cruz no time is given.
March 10th, 14 h. 8 m.—A light shock was felt in San Francisco.
” ” 16 h. 30 m.—Another shock at San Francisco, marked by two distinct vibrations and lasting three and one-half seconds.
March 20th, 23 h. 45 m.—A light shock of earthquake having four distinct tremors, and occupying a little more than three seconds.
March 22d, 13 h. 0 m.—A smart shock was felt at Stockton, causing some little commotion.
May 20th, 18 h. 1 m.—A light shock of earthquake at San Francisco. At Stockton the shock was quite severe and occurred nine minutes later. At San José it also was very sharp. At Napa the earthquake, which was quite severe at this place, occurred at 18 h. 57 m. At Sacramento the shocks occurred at 18 h.: and was very severe. There were two distinct waves felt at this locality. This earthquake was felt as far north as Long Valley, in Mendocino County, and was followed by two loud reports like artillery, almost instantly.
June 6th, 11 h. 7 m.—A light shock of earthquake at San Francisco.
June 22d, 20 h. 53 m.—A smart shock of earthquake at San Francisco, consisting of three distinct waves and a profound low rumbling sound. Each of the shocks were marked by a peculiar abruptness, like sudden sharp jolts. They were followed by a series of lessening tremors which gradually died away.
This earthquake was felt as far north as Healdsburg, (about 80 miles distant), at Napa, at Pacheco, at Stockton, and at San José, south of this city fifty-two miles, making a distance of one hundred and thirty-two miles, north and south, over which its influence was well marked.
July 5th, 20 h. 3 m.—An earthquake at San Francisco, not severe; this consisted of four distinct vibrations occurring during a period of seven minutes. The second vibration and the longest lasted nineteen seconds. The shortest vibration was six seconds in length. The elapsed time between the waves varied from forty seconds to one and one-fourth minutes.
July 21st, 2 h. 7 m.—A smart shock was felt at San Francisco.
” ” 22 h. 40 m. 38 s.—A very smart shock of earthquake at San Francisco, consisting of two waves at four seconds apart. The direction of the motion was north thirteen degrees east. The displacement was one and a fourth inches, at twenty feet four inches from the ground. Pendulum suspension eighteen inches.
The earthquake was experienced at San José at the same hour, and consisted of four strong shocks. At Stockton the earthquake was severe, and took place twelve minutes later than at this city. The earthquake was felt at Los Angeles, but was not very heavy. No time is given from this latter locality.
July 25th, 23 h. 56 m.—A shock of earthquake at Los Angeles.
Aug. 17th, 22 h. 39 m.—A light shock of earthquake at Nevada and vicinity.
Aug. 18th, 5 h. 18 m.—A very strong shock of earthquake was experienced at Grass Valley and Nevada, which threw down a wall of stone and brick in the well of Dr. Fellows. This earthquake was felt at Gibsonville at the north and at Marysville to the west; at the latter locality it was twelve minutes later than at Grass Valley.
Sept. 6th, 10 h. 3 m.—A shock of earthquake at San Francisco.
Sept. 20th, 11 h. 0 m.—A light shock of earthquake at San José; it was observed at the Mission Dolores.
Sept. 27th, 10 h. 32 m.—A heavy shock at Mission San Juan, Monterey Co.
Oct. 6th, 21 h. 9 m.—A smart shock of earthquake at San Francisco.
Oct. 14th, 1 h. 8 m.—Two heavy shocks of earthquake were felt at Mission San Juan, and another severe shock at 10 h. 25 m., the movement was from west to east.
Dec. 11th, 20 h. 52 m.—A shock of earthquake at San Francisco. This shock was felt at San José at 20 h. 51 m., and was evidently more severe there than at San Francisco.
During 1864, we have had twenty-one days on which earthquakes have occurred, and of at number there have been two days, (March 10th and July 21st) in which more than one shock has taken place within the twenty-four hours of each day.
The British Colonist, of Victoria, Vancouver Island, furnishes the following statement:
From a gentleman who has resided on Vancouver Island for 15 years, we learn that slight earthquakes have occurred annually, with one or two exceptions, during the entire period. Only on one occasion (1858) does he remember experiencing a shock at all approaching in severity that of Saturday morning, October 29th 1864. The oscillation, as on this last occasion, has almost invariably been from west to east: and he accounts for this, by supposing that the internal convulsion of the earth beneath, has to find vent in the crater of Mount Baker, situated to the east of us. This volcano has not had any visible eruption for several years. On the last occasion, it sent up a dense volume of smoke, and occasionally a bright flame was seen to issue from the fiery furnace. Another old resident informs us, that the appearance of the summit of Mount Baker has undergone a material change within late years, giving room for the conjecture that large portions have crumbled away and descended into the yawning abyss of the crater which lies between the two highest peaks.
Relating to earthquakes at San Francisco and its immediate vicinity, we have an item of interesting information relating to their effects at the Farrallones Islands, situated some fifteen miles to the west of the city. It appears, upon the testimony of the lighthouse-keeper at these Islands, and who has resided there for several years, (seven or eight), that but two of the whole number occurring at this city, have been felt at the Islands, and of these he made an official record. The first was the shock of Dec. 23d, 1862, and that of June 22d, 1864.
From 1857 to date, we have seven years, during which time twenty-five shocks have been authenticated at San Francisco, while two only of the number have been felt at the above locality west of the city.