﻿THE 
  GULF 
  STREAM 
  — 
  MARMBR 
  291 
  

  

  just 
  south 
  of 
  Cape 
  Florida. 
  In 
  constructing 
  the 
  velocity 
  curves 
  Wiist 
  

   made 
  use 
  of 
  Pillsbury's 
  observations; 
  and 
  for 
  the 
  deeper 
  parts, 
  for 
  

   which 
  no 
  observations 
  are 
  at 
  hand, 
  he 
  derived 
  the 
  necessary 
  data 
  from 
  

   a 
  consideration 
  of 
  the 
  temperature 
  and 
  salinity 
  observations, 
  which 
  

   here 
  extend 
  from 
  the 
  surface 
  to 
  the 
  bottom. 
  

  

  Within 
  the 
  Straits 
  of 
  Florida 
  the 
  Gulf 
  Stream 
  is 
  generally 
  pictured 
  

   as 
  a 
  swiftly 
  moving 
  stream 
  with 
  but 
  little 
  variation 
  in 
  velocity 
  from 
  

   surface 
  to 
  bottom. 
  Figure 
  3 
  shows, 
  however, 
  that 
  only 
  within 
  a 
  layer 
  

   of 
  about 
  200 
  fathoms 
  (1,200 
  feet) 
  does 
  the 
  velocity 
  exceed 
  1 
  knot. 
  

   Moreover, 
  near 
  the 
  bottom, 
  Pillsbury 
  found 
  the 
  current 
  setting 
  south- 
  

   erly, 
  that 
  is, 
  in 
  a 
  direction 
  opposite 
  to 
  that 
  of 
  the 
  main 
  stream. 
  This 
  

   was 
  taken 
  to 
  indicate 
  a 
  southerly 
  flowing 
  current, 
  deriving 
  perhaps 
  

   from 
  the 
  Labrador 
  Current. 
  It 
  appears, 
  however, 
  that 
  it 
  is 
  more 
  

   reasonably 
  to 
  be 
  ascribed 
  to 
  eddies 
  brought 
  about 
  by 
  the 
  upward- 
  

   sloping 
  bottom 
  within 
  the 
  Straits 
  of 
  Florida. 
  

  

  With 
  the 
  details 
  of 
  the 
  velocity 
  distribution 
  known, 
  it 
  becomes 
  

   possible 
  to 
  compute 
  the 
  volume 
  of 
  water 
  discharged 
  by 
  the 
  Gulf 
  Stream 
  

   through 
  the 
  Straits 
  of 
  Florida. 
  A 
  rough 
  estimate 
  is 
  easily 
  made 
  

   from 
  Figure 
  3. 
  In 
  round 
  numbers 
  the 
  channel 
  eastward 
  of 
  Cape 
  

   Florida 
  has 
  a 
  width 
  of 
  42 
  (geographical) 
  miles 
  and 
  an 
  average 
  depth 
  

   of 
  2,000 
  feet, 
  or 
  approximately 
  one-third 
  of 
  a 
  mile. 
  This 
  gives 
  the 
  

   area 
  of 
  the 
  cross 
  section 
  here 
  as 
  14 
  square 
  miles. 
  In 
  round 
  numbers, 
  

   also, 
  the 
  velocity 
  of 
  the 
  current 
  through 
  this 
  section 
  may 
  be 
  taken 
  

   as 
  1 
  knot. 
  Each 
  hour, 
  therefore, 
  the 
  Gulf 
  Stream 
  carries 
  14 
  cubic 
  

   miles 
  of 
  water 
  past 
  this 
  section 
  into 
  the 
  sea. 
  Since 
  a 
  geographical 
  

   mile 
  has 
  a 
  length 
  of 
  6,080 
  feet 
  and 
  a 
  cubic 
  foot 
  of 
  sea 
  water 
  weighs 
  

   approximately 
  64 
  pounds, 
  we 
  find 
  that 
  each 
  hour 
  the 
  Gulf 
  Stream 
  

   carries 
  100 
  billion 
  tons 
  of 
  water 
  past 
  Cape 
  Florida 
  into 
  the 
  sea. 
  

  

  The 
  above 
  calculation 
  is 
  clearly 
  no 
  more 
  than 
  a 
  rough 
  estimate; 
  

   but 
  it 
  demonstrates 
  that 
  the 
  hourly 
  volume 
  of 
  the 
  Gulf 
  Stream 
  is 
  to 
  

   be 
  reckoned 
  in 
  scores 
  of 
  billions 
  of 
  tons. 
  On 
  the 
  basis 
  of 
  his 
  observa- 
  

   vations 
  Pillsbury 
  calculated 
  the 
  hourly 
  volume 
  of 
  the 
  Gulf 
  Stream 
  

   thi'ough 
  the 
  Straits 
  of 
  Florida 
  as 
  90 
  billion 
  tons. 
  More 
  recently 
  

   Wiist, 
  on 
  the 
  basis 
  of 
  data 
  furnished 
  by 
  the 
  observations 
  and 
  amplified 
  

   by 
  dynamical 
  considerations, 
  derived 
  for 
  this 
  volume 
  89.96 
  cubic 
  

   kilometers, 
  or 
  14.1 
  cubic 
  miles, 
  which 
  equals 
  IOI/2 
  billion 
  tons. 
  In 
  

   round 
  numbers 
  we 
  may 
  therefore 
  take 
  the 
  average 
  hourly 
  volume 
  of 
  

   the 
  Gidf 
  Stream 
  through 
  the 
  Straits 
  of 
  Florida 
  to 
  be 
  100 
  billion 
  tons. 
  

  

  We 
  may 
  perhaps 
  appreciate 
  better 
  the 
  enormous 
  volume 
  of 
  water 
  

   that 
  the 
  Gulf 
  Stream 
  pours 
  into 
  the 
  sea 
  by 
  comparing 
  it 
  with 
  the 
  

   volume 
  discharged 
  by 
  the 
  Mississippi 
  River, 
  which 
  drains 
  more 
  than 
  

   40 
  per 
  cent 
  of 
  the 
  area 
  of 
  continental 
  United 
  States. 
  On 
  the 
  average 
  

   the 
  Mississippi 
  discharges 
  about 
  664,000 
  cubic 
  feet 
  of 
  water 
  into 
  the 
  

   Gulf 
  of 
  Mexico 
  each 
  second. 
  At 
  extreme 
  flood 
  stage 
  this 
  volume 
  

   becomes 
  multiplied 
  about 
  threefold, 
  mounting 
  to 
  about 
  1,800,000 
  

   82.^22—30 
  20 
  

  

  