TY - JOUR PY - 1988// TI - Atmospheric pressure changes due to volcanic eruptions and possible water level fluctuations JO - Natural hazards A1 - Danard, M. B. A1 - Murty, T. S. SP - 15 EP - 26 VL - 1 IS - 1 N2 - The data of Reed (1983) are analysed to produce the following empirical equations for the amplitude p 0 (overall fluctuation) in Pascals of the air pressure wave associated with a volcanic eruption of volume V km3 or a nuclear explosion of strength M Mt: Here s is the distance from the source in km. $$begin{gathered} log _{10} p_0 = 4.44 + log _{10} V - 0.84log _{10} s hfill \ {text{ }} = 3.44 + log _{10} M - 0.84log _{10} s. hfill \ end{gathered} $$ Garrett's (1970) theory is examined on the generation of water level fluctuations by an air pressure wave crossing a water depth discontinuity such as a continental shelf. The total amplitude of the ocean wave is determined to be where c 2 1 = gh 1, c 2 2 = gh 2, g is acceleration of gravity, h 1 and h 2 are the water depths on the ocean and shore side of the depth discontinuity, c is the speed of propagation of the air pressure wave, and ϱ is the water density. $$B = left[ {frac{{c_2^2 }}{{c^2 - c_2^2 }} + frac{{c^2 (c_1 - c_2 )}}{{(c - c_1 )(c^2 - c_2^2 )}}} right]frac{{p_0 }}{{gvarrho }}$$ It is calculated that a 10 km3 eruption at Mount St. Augustine would cause a 460 Pa air pressure wave and a discernible water level fluctuation at Vancouver Island of several cm amplitude.

Language: en

LA - en SN - 0921-030X UR - http://dx.doi.org/10.1007/BF00168219 ID - ref1 ER -