﻿260 
  Jag 
  gar 
  — 
  Lava 
  Flow 
  from 
  Mauna 
  Loa, 
  1916. 
  

  

  much 
  nearer 
  origin 
  and 
  felt 
  sharply 
  three 
  miles 
  (5 
  km.) 
  north- 
  

   east 
  of 
  Kilauea 
  crater, 
  the 
  larger 
  number 
  were 
  propagated 
  

   from 
  origins 
  as 
  far 
  as 
  the 
  Mauna 
  Loa 
  rifts. 
  

  

  This 
  September 
  crisis 
  of 
  1915 
  deserves 
  close 
  scrutiny 
  in 
  view 
  

   of 
  the 
  double 
  Mauna 
  Loa-Kilauea 
  culmination, 
  accompanied 
  

   with 
  earthquakes 
  and 
  intense 
  volcanic 
  vibration, 
  which 
  hap- 
  

   pened 
  eight 
  months 
  later. 
  A 
  similar 
  seismic 
  spasm, 
  premoni- 
  

   tory 
  to, 
  and 
  two 
  months 
  before, 
  the 
  1914 
  outbreak, 
  occurred 
  

   in 
  September, 
  1914, 
  when 
  twenty-nine 
  shocks 
  were 
  felt 
  at 
  

   Kapapala 
  on 
  the 
  southeast 
  flank 
  of 
  Mauna 
  Loa 
  from 
  Septem- 
  

   ber 
  27 
  to 
  September 
  28 
  and 
  the 
  seismologist 
  of 
  the 
  Observatory 
  

   reported* 
  that 
  " 
  without 
  question 
  this 
  forty-eight 
  hours 
  .... 
  

   was 
  a 
  period 
  more 
  active 
  seismically 
  than 
  any 
  interval 
  of 
  like 
  

   duration 
  since 
  the 
  establishment 
  of 
  this 
  station." 
  A 
  similar 
  but 
  

   milder 
  seismic 
  spasm 
  had 
  occurred 
  during 
  the 
  early 
  days 
  of 
  

   July, 
  1914 
  (fig. 
  1). 
  Coordinately 
  with 
  each 
  of 
  these 
  premoni- 
  

   tory 
  seismic 
  events 
  of 
  1914 
  there 
  was 
  a 
  spurt 
  of 
  rather 
  grad- 
  

   ual 
  rising 
  of 
  Kilauea 
  lava 
  followed 
  by 
  relatively 
  sudden 
  subsi- 
  

   dence. 
  The 
  earthquakes, 
  however, 
  showed 
  origins 
  more 
  

   distant 
  than 
  Halemaumau 
  and 
  were 
  believed 
  to 
  arise 
  on 
  the 
  

   Mauna 
  Loa 
  rifts. 
  

  

  The 
  1915 
  spasm 
  as 
  instrumentally 
  recorded 
  at 
  the 
  Observa- 
  

   tory 
  was 
  described 
  as 
  followsf 
  by 
  H. 
  O. 
  Wood, 
  seismologist 
  : 
  

   "In 
  the 
  following 
  six 
  days 
  (after 
  September 
  16, 
  1915) 
  sixteen 
  

   well-marked 
  local 
  earthquakes 
  were 
  registered. 
  None 
  of 
  these 
  

   were 
  felt 
  close 
  by 
  the 
  Observatory, 
  but 
  several, 
  one 
  in 
  partic- 
  

   ular, 
  were 
  felt 
  at 
  Hilo, 
  Kapapala 
  and 
  on 
  the 
  Hamakua 
  coast. 
  

  

  "Most 
  of 
  these, 
  while 
  distinctly 
  of 
  local 
  origin, 
  were 
  from 
  more 
  

   distant 
  sources 
  than 
  the 
  average 
  of 
  local 
  shocks. 
  Besides 
  these 
  

   there 
  were 
  thirteen, 
  more 
  or 
  less, 
  seismic 
  disturbances 
  grading 
  

   in 
  character 
  and 
  energy 
  from 
  well-marked 
  earthquake 
  wave- 
  

   groups 
  to 
  those 
  usually 
  considered 
  as 
  volcanic-vibration 
  wave 
  

   groups. 
  All 
  these 
  were 
  of 
  very 
  small 
  amplitude 
  ; 
  and 
  there 
  is 
  

   no 
  genetic 
  distinction 
  between 
  an 
  earthquake 
  record 
  and 
  a 
  

   volcanic-vibration 
  record. 
  The 
  former 
  is 
  a 
  group 
  of 
  earth- 
  

   waves 
  with 
  a 
  distinct 
  indication 
  of 
  fore-phases. 
  Though 
  

   Mauna 
  Loa 
  shows 
  no 
  sign 
  from 
  the 
  Observatory, 
  the 
  possi- 
  

   bility 
  that 
  these 
  disturbances 
  point 
  to 
  renewed 
  action 
  there 
  

   cannot 
  be 
  overlooked. 
  

  

  "The 
  week 
  ending 
  with 
  September 
  29, 
  1915, 
  has 
  been 
  

   marked 
  by 
  extraordinary 
  local 
  seismic 
  activity 
  — 
  though 
  none 
  

   of 
  the 
  earthquakes 
  registered 
  have 
  been 
  felt 
  at 
  the 
  Observa- 
  

   tory 
  or 
  at 
  the 
  Volcano 
  House. 
  However, 
  within 
  three 
  miles 
  

   (5 
  km.) 
  in 
  the 
  direction 
  of 
  Hilo 
  several 
  have 
  been 
  felt, 
  partic- 
  

   ularly 
  on 
  September 
  26, 
  some 
  quite 
  sharply. 
  

  

  *Bull. 
  Hawaiian 
  Vole. 
  Obs'y, 
  Nov., 
  1914, 
  p. 
  134. 
  

  

  f 
  Bull. 
  Hawaiian 
  Vole. 
  Obs'y, 
  Sept., 
  1915, 
  pp. 
  100 
  and 
  103. 
  

  

  