00000158 |
Previous | 158 of 595 | Next |
|
small (250x250 max)
medium (500x500 max)
Large
Extra Large
large ( > 500x500)
Full Resolution
All (PDF)
|
ENCROACHMENT OF THE SEA. 141
transformed into shingle and sand. Toward the end of the year 1862,
during one of the most terrible tempests of the century, M. Lennier saw
the sea batter down the rocks of La Heve to a thickness of more than
fifty feet. Since the year 1100, the waters of the Channel, aided by rain,
frost, and other agents, that act strongly on the upper strata, have cut
down this cliff by more than 1500 yards—that is to say, more than two
yards per year. The spot where the village of Sainte Adresse formerly
stood has given way before the flood, and is replaced by the bank of
I'Eclat.* M. Bouniceau, one of those savants who have specially studied
the phenomena of erosion of shores, estimates the fraction of cliff which
is carried away by the sea on the coasts of Calvados at above a quarter
of a yard on an average yearly, while on the coasts of Seine Inferieure
the annual erosion may be considered as nearly a foot.
In some places on the southern and eastern coasts of England, the invasions of the. sea take place with an equal or even superior rapidity, for
the farmers generally count on the loss of about a yard per year along
the cliff.f To the east of the peninsula of Kent, the waters have advanced more than three miles toward the west since the Roman period.
In their successive invasions, they have submerged the vast domains of
the Saxon Earl Goodwin, and have replaced them by the terrible Goodwin Sands, where so many ships are lost every year; and they have
transformed the narrow lagune of the Downs into great open roads. According to the calculations of M. Marchal,| the total amount of denudation which the waters of the eastern part of the Channel carry on every
year is equal to above thirteen millions of cubic yards.
The Straits of Dover are being continually enlarged by the action of
atmospheric influences, the waves, and the current which flows from the
Channel into the North Sea. The patient researches of M. Thome de
Gamond, an engineer to whom we owe the fine project of the international tunnel between France and England, have proved that the cliff of
Gris-Nez, the nearest point of the French coast to Great Britain, loses on
an average more than twenty-seven yards per century. If in former ages
the progress of erosion was not more rapid, it would be about 60,000
years before the present epoch that the isthmus connecting England with
the continent was broken by the pressure of the waves. Nevertheless, it
is impossible to indicate any date, since at this place the ground has sunk
and risen at various intervals: ancient beaches four or five yards above
the present level of the sea, as well as submerged forests, testify to these
successive oscillations.§
Along the coast of France, to the east of Cape Antifer, the pebbles resulting from the denudation of the cliffs are continually advancing toward the mouth of the Somme. Arrested at about six miles beyond these
* Lamblardie, Bande, Revue des deux Mondes.
t Beete Jukes, School Manual of Geology, p. 90.
X Annales des Ponts et Chaussees, ler sem., p. 201.
§ Day, Geological Magazine, 1866.
| Title | The ocean, atmosphere, and life |
| Creator | Reclus, Elisée |
| Publisher | Harper |
| Place of Publication | New York |
| Date | 1873 |
| Language | eng |
| Type | Books/Pamphlets |
| Title | 00000158 |
| Type | Books/Pamphlets |
| Transcript | ENCROACHMENT OF THE SEA. 141 transformed into shingle and sand. Toward the end of the year 1862, during one of the most terrible tempests of the century, M. Lennier saw the sea batter down the rocks of La Heve to a thickness of more than fifty feet. Since the year 1100, the waters of the Channel, aided by rain, frost, and other agents, that act strongly on the upper strata, have cut down this cliff by more than 1500 yards—that is to say, more than two yards per year. The spot where the village of Sainte Adresse formerly stood has given way before the flood, and is replaced by the bank of I'Eclat.* M. Bouniceau, one of those savants who have specially studied the phenomena of erosion of shores, estimates the fraction of cliff which is carried away by the sea on the coasts of Calvados at above a quarter of a yard on an average yearly, while on the coasts of Seine Inferieure the annual erosion may be considered as nearly a foot. In some places on the southern and eastern coasts of England, the invasions of the. sea take place with an equal or even superior rapidity, for the farmers generally count on the loss of about a yard per year along the cliff.f To the east of the peninsula of Kent, the waters have advanced more than three miles toward the west since the Roman period. In their successive invasions, they have submerged the vast domains of the Saxon Earl Goodwin, and have replaced them by the terrible Goodwin Sands, where so many ships are lost every year; and they have transformed the narrow lagune of the Downs into great open roads. According to the calculations of M. Marchal,| the total amount of denudation which the waters of the eastern part of the Channel carry on every year is equal to above thirteen millions of cubic yards. The Straits of Dover are being continually enlarged by the action of atmospheric influences, the waves, and the current which flows from the Channel into the North Sea. The patient researches of M. Thome de Gamond, an engineer to whom we owe the fine project of the international tunnel between France and England, have proved that the cliff of Gris-Nez, the nearest point of the French coast to Great Britain, loses on an average more than twenty-seven yards per century. If in former ages the progress of erosion was not more rapid, it would be about 60,000 years before the present epoch that the isthmus connecting England with the continent was broken by the pressure of the waves. Nevertheless, it is impossible to indicate any date, since at this place the ground has sunk and risen at various intervals: ancient beaches four or five yards above the present level of the sea, as well as submerged forests, testify to these successive oscillations.§ Along the coast of France, to the east of Cape Antifer, the pebbles resulting from the denudation of the cliffs are continually advancing toward the mouth of the Somme. Arrested at about six miles beyond these * Lamblardie, Bande, Revue des deux Mondes. t Beete Jukes, School Manual of Geology, p. 90. X Annales des Ponts et Chaussees, ler sem., p. 201. § Day, Geological Magazine, 1866. |
|
|
|
|
|
|
| B |
|
| C |
|
| G |
|
| H |
|
| M |
|
| T |
|
| U |
|
| Y |
|
|
|
