Official Meter Chart Huntington Beach Showing Earthquake Shocks - March 10, 11, 1933

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Official Meter Chart from Huntington Beach Showing Earthquake Shocks March 10, 11, 1933 9 P.M. 2 P.M. 10 P.M. 1 P.M. 10-G 11 P.M. METRIC METAL WORKS, ERIE, PA. OP. NO. LEASE NOON CHART PUT ON TAKEN OFF 12 NIGHT 10-30 AM 10-30 A.M 12 MAR. 10-1933 MAR I1- 1931 PLANT PRING SIGNLD 11 A.M. 1 A.M. 2 A.M. 10 A.M. %23 9 A.M. 8 A.M. Official Navy Seismographical Records. 1906 San Francisco . . 1924 Tokio 1925 Santa Barbara 1933 Long Beach Force 2-5 5-8 3-4 4-6 66 66 66 Area Raised, 30 inches. Force, 8 ft. North back 5½ ft. in 11 seconds 3 P.M. 4 P.M. 5 P.M. 6 P.M. 7 P.M. 8 P.M. 7 A.M. 6 A.M. 5 A.M. 4 A.M. 3 A.M.

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EARTHQUAKE THEORIES From a personal interview with Dr. Gutenberg, Caltech. (Reprint from L. A. Times) Q. What is a tectonic earthquake? A. One caused by strains in earth's structure, not by volcanic or external forces. Q. Why should the pressure of continents against ocean beds be regarded as one cause of earthquakes ? A. Being denser than water, high shore lands overload the crust around ocean beds, causing faults and accompanying quakes. Land weighs about one-third more than water. Q. What has the cooling of the earth to do with earth- quakes ? A. As the interior cools it contracts and causes stresses. Q. What influence has the earth's magnetic poles on earthquakes ? A. Migrating, the poles create strains by pulling from varying directions. Q. What is meant by "trigger forces”? A. Forces which release an earthquake when conditions are set-like a trigger finger letting off a blast. Q. What trigger forces affect earthquakes ? A. Air press- ure, tides, heavy rains, possibly moon's gravity, etc. Q. What does the first shock signify? A. That something in the crust has broken. Q. What do after-shocks signify? A. That readjustments are occurring in the neighborhood. Q. Do outside influences, such as the sun, moon and planets, cause certain earthquakes ? A. Not likely; the causes come from inside, not from outside. Q. During a tectonic earthquake, does the ground move vertically or horizontally? A. Both ways; near the center vertical movements prevail; farther away horizontal movements prevail. A. NIELEN, 404 N. Commonwealth Ave., Los Angeles, Calif.