﻿Jaggar 
  — 
  Lava 
  Flow 
  from 
  Mauna 
  Loa, 
  1916. 
  265 
  

  

  the 
  outbreak 
  and 
  that 
  the 
  felt 
  earthquakes 
  did 
  not 
  travel 
  far 
  

   from 
  the 
  source 
  at 
  the 
  time 
  of 
  actual 
  rapid 
  rise 
  of 
  lava 
  near 
  

   the 
  surface. 
  

  

  Cursory 
  inspection 
  of 
  the 
  seismograms 
  of 
  the 
  Mauna 
  Loa 
  

   eruption 
  period 
  of 
  1916 
  shows 
  

  

  May 
  19, 
  morning, 
  continuous 
  trembling. 
  

  

  19-20, 
  trembling 
  followed 
  by 
  a 
  shock. 
  

  

  20-21, 
  trembling 
  followed 
  by 
  several 
  shocks. 
  

  

  21-22, 
  some 
  trembling, 
  but 
  increase 
  of 
  definite 
  shocks. 
  

  

  22-23, 
  many 
  distinct 
  shocks 
  of 
  large 
  amplitude. 
  

  

  23-31, 
  earthquakes 
  continued, 
  generally 
  decreasing 
  in 
  

   amplitude, 
  except 
  for 
  occasional 
  ones 
  of 
  very 
  

   large 
  amplitude. 
  One 
  of 
  these 
  appears 
  May 
  

   25-26 
  and 
  another 
  May 
  30-31. 
  

   June 
  1-3, 
  Four 
  ordinary 
  earthquakes. 
  

  

  The 
  larger 
  amplitude 
  shocks 
  of 
  the 
  closing 
  days 
  of 
  the 
  erup- 
  

   tion 
  were 
  felt 
  especially 
  strongly 
  on 
  the 
  Mauna 
  Loa 
  slopes. 
  

   The 
  writer 
  felt 
  a 
  sharp 
  shock 
  at 
  Waiohinu 
  about 
  1:50 
  a. 
  m., 
  

   May 
  27. 
  Mr. 
  Wood 
  was 
  on 
  the 
  mountain 
  at 
  an 
  old 
  cone 
  east 
  

   of 
  the 
  lava 
  source 
  on 
  May 
  30, 
  when* 
  " 
  at 
  about 
  8:45 
  p. 
  m., 
  a 
  

   short 
  sharp 
  earthquake 
  occurred, 
  plainly 
  felt 
  by 
  all 
  three 
  of 
  us 
  

   sitting 
  or 
  reclining 
  on 
  the 
  cinders 
  in 
  the 
  reentrant 
  of 
  the 
  cone. 
  

   This 
  shock 
  was 
  felt 
  sharply 
  at 
  Waiohinu 
  and 
  at 
  Kapapala. 
  At 
  

   Hilea 
  it 
  was 
  felt 
  as 
  the 
  strongest 
  shock 
  of 
  the 
  entire 
  series 
  

   connected 
  with 
  this 
  eruption. 
  Within 
  less 
  than 
  a 
  minute 
  after 
  

   the 
  shock 
  there 
  occurred 
  a 
  spasm 
  of 
  greatly 
  increased 
  action 
  

   at 
  the 
  southern 
  active 
  lava 
  vent, 
  with 
  the 
  jetting 
  of 
  lumps 
  of 
  

   lava 
  and 
  a 
  great 
  increase 
  in 
  the 
  flow. 
  This 
  quickly 
  declined 
  to 
  

   normal." 
  

  

  This 
  observation 
  is 
  of 
  interest 
  in 
  showing 
  the 
  immediate 
  

   kinship 
  of 
  the 
  lava-gushing 
  and 
  the 
  earthquakes. 
  The 
  above 
  

   cited 
  sequence 
  in 
  the 
  seismograms 
  show 
  T 
  s 
  that 
  the 
  earthquakes 
  

   waxed 
  from 
  a 
  continuous 
  jarring 
  to 
  large 
  numbers 
  of 
  moderate 
  

   shocks 
  in 
  four 
  days, 
  and 
  thereafter 
  for 
  eight 
  days 
  there 
  was 
  

   fairly 
  regular 
  decrease 
  in 
  numbers 
  of 
  shocks 
  and 
  increase 
  in 
  

   their 
  occasional 
  intensity. 
  The 
  approximate 
  numbers 
  of 
  earth- 
  

   quakes 
  per 
  day 
  are 
  shown 
  diagrammatically 
  in 
  tig. 
  2 
  ; 
  the 
  

   column 
  of 
  figures 
  on 
  the 
  right 
  of 
  diagram 
  signifies 
  numbers 
  of 
  

   earthquakes 
  and 
  larger 
  wave 
  groups 
  ; 
  the 
  length 
  of 
  the 
  ver- 
  

   tical 
  line 
  corresponds 
  to 
  number 
  of 
  such 
  shocks 
  counted 
  on 
  the 
  

   seismograms 
  for 
  each 
  twenty-four 
  hour 
  period 
  following 
  the 
  

   morning 
  of 
  the 
  date 
  indicated. 
  

  

  The 
  swarm 
  of 
  local 
  earthquakes 
  which 
  accompanied 
  the 
  sud- 
  

   den 
  drainage 
  of 
  the 
  lava 
  from 
  Halemaumau, 
  June 
  1 
  to 
  7, 
  1916, 
  

   increased 
  in 
  number 
  to 
  about 
  double 
  the 
  maximum 
  registered 
  

  

  ♦Bull. 
  Hawaiian 
  Vole. 
  Obs'y, 
  June, 
  1916, 
  p. 
  54. 
  

  

  