Evening star. [volume] (Washington, D.C.) 1854-1972, 1902-05-31
VOLCANIC ERUPT|ONS
The Fiery Forces That Cause
Destruction.
CA USES ANALYZED
LOOKING INTO THE FOUNDATIONS
OF vEsUvIUs.
How the Heat Of the Earth's Crust In
creases as It is Pene-
trated.
"A USES ANALYZED
Copyright, 1902

Written for The Evening Star
Inc recent volcanic outbreaks In the
west Indies have aroused great interest in
this particular form through which the
interior heat and energy of the earth man.
Hest themselves. and have raised questions
or scientific nature in the minds Of a
great many who had not previously given
them much attention. These questions are
not only attractive, but direct investigation
OF them involves some elements of danger
and they are, withal bit uncanny
All That We know In a general way about
volcanoes and their attendant earthquakes
has been accumulated by patient observa-
ton or both active and extinct cones and
by Interpretation of the observations in ac-
cordance with sound principles. Geology in
this particular does us all great service be-
cause 1t brings to our aid in connection
with the outbreaks in the Lesser Antilles
the results Of much careful work in all
quarters of the globe lasting through CEN
turtles and performed by many observers
If. then, we briefly state the order of
events in the West Indies we may after
ward see how well they conform to a few
general principles which have been estab-
lished in this matter,
Mount Pelee. in Martinique and La Sou
friere. in st. Vincent, have been recognized
as old craters since their discovery but it
is long time-ninety years. in fact-since
the latter was active. A lake even accumu-
lated In one of the craterS. Gradually In
the early part of May there We're symp-
toms of reviving activity. Earthquake
shocks were felt in their neighborhood:
clouds of steam and other gases started up
from the old vents and showers of dust
ana stones We're blown into the air. because
the vapors burst forth with explosive vio-
lence. AS the days passed the violence in
creased, and soon an explosion of special
efficiency in Mount Pelee tapped off a flood
or molten rock. which coursed in a de-
structive tide down the mountain A day
or two afterward a furious outburst cast
the hot dust and clouds of lava over St
Pierre and utterly destroyed it.
On ST. Vincent, at this writing dust and
larger fragments and gases have been the
main emissions, and have caused the prin-
cipal loss of life and damage II is re-
ported that the bottom of the sea has sunk
several fathoms near Georgetown. and that
thus considerable dislocation of the crust
is indicated.
Raised From Seas Depths.
All the Lesser Antilles, from Saba
through the Grenadines and Grenada. are
Of volcanic origin, and they hail from the
depths Of the sea. We have no means of
knowing their exact structure, but from
our fuller knowledge of Vesuvlus. as shown
In the accompanying diagram, we can draw
pretty close inference.
Vesuvius rests upon the following de-
scribed foundation, as has been shown by
deep bor1ngs in Naples and by the mountain
ridge of st. Angelo farther southeast.
The lowest stratum Is limestone of unde-
termined thickness. The volcano occasion
ally casts out blocks Of 1t borne aloft from
below.
Next above this Is $50 feet of sandstone;
then 700 feet of calcareous sandstone.
On the top of the last named (first as
submarine vent and apparently in about
600 feet of water) the young volcano built
up a great layer of dust and fragments GOO
feet thick. Throughout this material are
found marine shells. When the COO feet had
been accumulated the vent had risen above
the water and was able to construct the old
crater known to the ancents But before
human records begin the activity ceased,
and at 700 B. c. the cone was cold and
dead. Suddenly, In the year 63 A. d. II
showed signs of activity, and sixteen years
after the usual warnings it broke out ex-
plosively. in 20 A. D., and buried up Pom
pei. with it's thousands of Inhabitants
From that time to the present 1t has been
quiet only for comparatively short periods.
In much the same way the cones and
islands of the Lesser Antilles must have
been reared. During periods of activity
beds of fine and coarse fragments of vol
canic rock have gathered in great quantity
Floods of lava and large masses intruded
into assures have bound them into solid
aggregate; islands and island cones have
been raised above the until the present
conditions have been reached.
Cause Of Eruptions.
Now, why do volcanoes break out? A
number of points are involved In an answer
to this question. We know, IN the first
place, that the earth grows hotter as we
descend and at rates that have been meas
A HEAD &c