﻿266 
  Jag 
  gar 
  — 
  Lava 
  Flow 
  from 
  Mauna 
  Loa, 
  1916. 
  

  

  during 
  the 
  May 
  crisis 
  in 
  a 
  similar 
  period 
  of 
  four 
  days 
  from 
  

   June 
  3 
  to 
  6 
  and 
  declined 
  more 
  abruptly, 
  the 
  greatest 
  number 
  

   of 
  shocks 
  being 
  recorded 
  and 
  also 
  felt 
  during 
  the 
  twenty 
  -four 
  

   hour 
  period 
  following 
  the 
  morning 
  of 
  June 
  5. 
  This 
  happened 
  

   simultaneously 
  with 
  the 
  most 
  rapid 
  fall 
  of 
  the 
  lava. 
  The 
  

   sequence 
  is 
  shown 
  in 
  fig. 
  2, 
  and 
  the 
  following 
  notes 
  were 
  

   made 
  by 
  the 
  writer 
  from 
  casual 
  inspection 
  of 
  the 
  seismograms 
  : 
  

  

  June 
  1-2, 
  two 
  shocks. 
  

   2-3, 
  two 
  shocks. 
  

   3-4, 
  eight 
  very 
  small 
  shocks. 
  

   4-5, 
  69 
  shocks 
  of 
  various 
  amplitudes. 
  

   5-6, 
  about 
  2J7 
  shocks 
  ; 
  but 
  from 
  noon 
  to 
  6 
  p. 
  m. 
  June 
  

  

  5 
  increasingly, 
  a 
  steady 
  trembling 
  followed 
  by 
  

  

  steady 
  decline. 
  

   6-1, 
  43 
  definite 
  shocks, 
  one 
  of 
  large 
  amplitude 
  but 
  not 
  

  

  larger 
  than 
  some 
  of 
  June 
  5. 
  

   1-8, 
  25 
  definite 
  shocks, 
  some 
  rather 
  strong. 
  

   8-9, 
  ] 
  2 
  very 
  weak 
  shocks. 
  

  

  9-10, 
  9 
  very 
  small 
  shocks 
  and 
  one 
  very 
  strong 
  one. 
  

   10-11, 
  13 
  feeble 
  shocks. 
  

   11-12, 
  4 
  shocks, 
  one 
  a 
  considerable 
  earthquake 
  followed 
  

  

  by 
  continuous 
  trembling 
  for 
  three 
  hours. 
  

  

  This 
  second 
  seismic 
  spasm 
  was 
  described 
  by 
  the 
  seismolo- 
  

   gist* 
  as 
  comprised 
  wholly 
  of 
  local 
  shocks 
  of 
  feeble 
  character 
  

   felt 
  near 
  Kilauea 
  crater 
  but 
  attracting 
  no 
  attention 
  at 
  Hilo 
  or 
  

   Pahala. 
  None 
  was 
  stronger 
  than 
  III 
  of 
  the 
  Rossi-Forel 
  scale. 
  

   They 
  proceeded 
  from 
  origins 
  nearer 
  to 
  the 
  Observatory 
  than 
  the 
  

   shocks 
  of 
  the 
  May 
  spasm. 
  Volcanic 
  vibration 
  exhibited 
  larger 
  

   amplitude 
  than 
  usual 
  during 
  the 
  week 
  of 
  this 
  June 
  crisis 
  and 
  

   the 
  tilting 
  of 
  the 
  ground 
  as 
  registered 
  seismometrically 
  changed 
  

   from 
  northeastward 
  to 
  southwestward 
  about 
  the 
  time 
  of 
  the 
  

   great 
  subsidence. 
  

  

  Explosion 
  of 
  May 
  19, 
  1916. 
  

  

  The 
  first 
  recorded 
  symptoms 
  of 
  actual 
  outbreak 
  on 
  Mauna 
  Loa 
  

   in 
  1916 
  were 
  earthquakes 
  recorded 
  in 
  a 
  swarm 
  by 
  the 
  seismo- 
  

   graphs 
  during 
  the 
  very 
  early 
  morning 
  hours 
  of 
  May 
  19, 
  and 
  felt, 
  

   in 
  part, 
  as 
  smart 
  shocks 
  at 
  the 
  southern 
  end 
  of 
  the 
  island 
  of 
  

   Hawaii. 
  Glow 
  and 
  fume, 
  also, 
  above 
  the 
  mountain 
  were 
  

   reported 
  seen 
  before 
  daybreak 
  from 
  a 
  vessel. 
  Nothing 
  was 
  

   seen 
  from 
  the 
  vicinity 
  of 
  the 
  Observatory 
  until 
  7 
  a. 
  m., 
  when 
  

   a 
  white 
  cumulus 
  rose 
  above 
  the 
  profile 
  of 
  Mauna 
  Loa 
  south 
  of 
  

   the 
  summit 
  region 
  and 
  developed 
  two 
  pronounced 
  jets 
  of 
  fume 
  

   and 
  a 
  vortex 
  ring. 
  At 
  8 
  a. 
  m. 
  the 
  two 
  jets 
  were 
  united 
  into 
  

   one 
  and 
  the 
  column 
  was 
  20,000 
  feet 
  (6100 
  m.) 
  high 
  above 
  its 
  

   base 
  (fig. 
  3). 
  The 
  higher 
  fume 
  jet 
  bore 
  approximately 
  S. 
  

  

  * 
  Bull. 
  Hawn. 
  Vole. 
  Obs'y, 
  June, 
  1916, 
  p. 
  49. 
  

  

  