Catoctin clarion. [volume] (Mechanicstown, Md.) 1871-1940, 1919-12-04
GULF FLOODS DUE
TO DROWNED KEYS
Cause of Corpus Christi Disas.
ter Is Explained.
HOW HOLLAND IS PROTECTED

as the Stanch Sea Walls at Calves
ton Have Prevented Recurrence OF
Disaster Of 900-Subsidence Of
Gulf Coast Is Estimated at About
One Foot Per Century.
An explanation of the coastal for
nation which contributed to the ter
rible inroads of the floods that all but
wiped out the city of Corpus Christi,
Tex, and devastated other gulf towns
Is contained in bulletin from the
Washington headquarters of the Ma.
fiOnai Geographic society.
The bulletin recalls that the Calves.
ron flood of 1900, which resulted In
the erection of the stanch sea walls
that prevented recurrence Of DESC
lation at Galveston. was not the first
calamity of that sort which has visited
southern cities.
Witness the swallowing Of L'Isle
Derniere, health and pleasure resort
Of New Orleans, with most of its
transient population, Just A years be-
fore Galveston" the bulletin says,
quoting from communication to the
society.
Florida Keys Farther Out.
"The student who scans the shores
of Atlantic and gulf. either on the
ground or on the admirable maps Of
the coast and geodetic survey and the
hydrogl aphic Office Of our navy, soon
perceives that the relations between
wave-built bars and wave-cut sea-
cliffs vary from coast stretch to coast
stretch. On the New Jersey coast the
bars are beaten we'll back to or beyond
the line of the seacliffs, so that the
ponds or sounds behind the bars are
relatively short and discOntinuous;
along the Florida coasts the keys
stand farther out to sea and are sepa-
rated from the mainland by great
elongated sounds often affording nav
igable waterways; while about the
northern shores Of the gulf the rela-
lions of the keys to sounds are more
variable.
"Closcr study serves to interpret
these variable relations. From Florida
westward to Mobile bay the keys are
nearly continuous and the sounds long
and narrow; thence westward to
Lake Borgne the typical keys are lost.
though their lines continue in series
of islands-Ship island, Horn island.
Cat island, etc.-separated from tn"
mainland by the broad Mississippi
sound: still farther westward II new
series of keys, erratic in form and
trend. appears In the Chandelier
islands, and beyond the delta there Is
a corresponding (and correspondingly
erratic) Sc es of low keys sti itching
W ~. rd neagiy G. G;.ite to Al -
t,.laya bay.
kc IS in Process Of Growth.
"Now the mainland shore OF MIS-
Gissippi sound is marked by series
of small and narrow keys and sounds
evidently in process of growth, but
much less advanced than those east of
Mobile bay; and these are among the
evidences that along this stretch Of
shore the gulf has encroached on the
land to such an extent as to leave the
original keys 20 to 40 miles behind.
similarly the Chandelier keys and
the corresponding series west of the
delta are small and new and obviously
connected with the delta building.
"West of Atchafalaya bay the coast
is characterized by the absence of
keys and sounds, save of the infantile
sort, like those OF The inland shore Of
Mississippi sound; so that this shore
seems incOngruouS with the rest until
the student discovers the long line Of
completely submerged keys-Sabine
bank, Trinity shoal. Ship shoal, etc
in a position precisely corresponding
TO the islands south of Mississippi
sound and forming direct submarine
connection (save as cut off by the
delta) between these islands Of the
eastern gulf and the well-developed
keys of the southern Texas shore.
"The position Of these banks, like
that of the Horn island and its fell
lows, is such as to demonstrate that
the waters have invaded the mainland.
ard that west of the delta the en-
croachment has been sufficient not
merely to push back the shore line
so to 100 miles, but completely to sub
merge the ancient keys.
'"rhe most striking feature of these
drowned and half-drowned keys Is
their symmetric arrangement; except
for the interruption by the delta with
its new and lesser sand banks), the
great bars form sweeping curve reg
ular as the beach line of landlocked
bay, and hence afford rough measure
of the 1utbuilding of the delta as well
rs of the invasion of the gulf on its
tanks.
Hardly less striking than the SYM
metry of the series Is the closeness Of
continuity between keys and banks;
and 1t Is q significant fact that Gal
weston island is the northwestern
terminus of the west coast system Of
keys, the last stretch of these sand
banks still rising above the level of
the tide.
"It Is the business of the geologist to
detect and weigh the evidences of sub
sidence or elevation of coasts and to
estimate the rates of movement for
the guidance of local residents and In
veStcrs: and 1t behOoves such citizens
to avail themselves of the scientific re-
searches.