UK. International Association of Sedimentologists, 5, 51–64.
Special Publication.
Klein, G. d V., 1970. Depositional and dispersal dynamics of intertidal sand bars. Journal of Sedimentary Petrology, 40,
1095–1127.
Middleton, G. V. (ed.), 1965. Primary Sedimentary Structures and
Their Hydrodynamic Interpretation – A Symposium. Tulsa: Society of Economic Paleontologists and Mineralogists. Special publication number, 12.
Pettijohn, F. J., and Potter, P. E., 1964. Atlas and Glossary of Primary Sedimentary Structures. New York: Springer.
Potter, P. E., and Pettijohn, F. J., 1977. Paleocurrents and Basin
Analysis, 2nd edn. New York: Springer.
Reineck, H. E., and Singh, I. B., 1980. Depositional Sedimentary
Environments. New York: Springer.
Reineck, H. E., and Wunderlich, F., 1968. Classification and Origin
of Flaser and Lenticular Bedding. Sedimentology. New York:
Wiley.
Terwindt, J. H. J., 1988. Paleo-tidal construction of inshore tidal
depositional environments. In de Boer, P. L., van Gelder, A.,
and Nio, S. D. (eds.), Tide-Influenced Sedimentary Environments and Facies. Dordrecht: D. Reidel Publishing Company,
pp. 233–264.
SEICHE
Murat Aksel
Civil Engineering Department, Istanbul Kultur University
Atakoy Campus, Istanbul, Turkey
Synonyms
Eagre; Sea swell
Definition
A seiche is a stationary wave oscillation that causes water
surface oscillations in any period and height under the
effects of different forces such as an earthquake, wind,
barometric pressure, and tide. It was initially described
by the Swiss hydrologist François-Alphonse Forel in
1890, who made the first scientific observations in Lake
Geneva, Switzerland (Darwin, 1898).
Description
The period of a seiche varies from a few minutes to
an hour or more. Wind is the most common seiche producing force, causing water surface heaves against the
downwind shore. Windbreaks cause water surface
oscillation. The period of a seiche is calculated using
Merian’s formula:
T ¼
1
n
2L
ffiffiffiffiffi
gd
p
ð1Þ
where T is the period of the seiche, n is the number of
the nodes of seiche, L is the mean length of the basin,
d is the mean depth, and g is the acceleration of gravity
(Chow, 1964).
Bibliography
Chow, V. T., 1964. Handbook of Applied Hydrology. New York:
McGraw-Hill.
Darwin, G. H., 1898. The Tides and Kindred Phenomena in the
Solar System. New York: Houghton, Mifflin and Company.
Tver, D. F., 1979. Ocean and Marine Dictionary. Ithaca: Cornell
Maritime Pr./Tidewater Publications.
SHANNON-WEAVER DIVERSITY INDEX
Selene Ortiz-Burgos
Facultad de Estudios Superiores Zaragoza, Universidad
Nacional Autónoma de México (UNAM), Delegación
Iztapalapa, DF, México
Synonyms
Shannon index; Shannon information index; ShannonWiener index
Definition
The Shannon-Weaver diversity index is based on communication theory. The uncertainty is measured by the Shannon Function “H
0 .” This term is the measure
corresponding to the entropy concept defined by
H
0
¼ À
X n
n¼1
pi
à ln p i
ð
Þ
ð1Þ
where H
0 is the diversity index, p i is the proportion of each
species in the sample, and ln p i is the natural logarithm of
this proportion (Shannon and Weaver, 1949; Spellerberg
and Fedor, 2003; Magurran, 2004).
Description
The Shannon-Weaver diversity index is one widely used
index for comparing diversity between various habitats
(Clarke and Warwick, 2001). It assumes that individuals
are randomly sampled from an independent large population, and all the species are represented in the sample
(Shannon and Weaver, 1949). The value of the ShannonWeaver diversity index usually ranges from 1.5 to 3.5
and only rarely exceeds 4.5.
The principal objective of a diversity index is to obtain
a quantitative estimate of biological variability that can be
used to compare biological entities in space or in time.
This index takes into account two different aspects that
contribute to the concept of diversity in a community: species richness and evenness.
Bibliography
Clarke, K. R., and Warwick, R. M., 2001. Changes in Marine Communities: An Approach to Statistical Analysis and Interpretation,
2nd edn. Plymouth: PRIMER-E.
Magurran, A., 2004. Measuring Biological Diversity. Oxford:
Blackwell.
572
SEICHE
Special Publication.
Klein, G. d V., 1970. Depositional and dispersal dynamics of intertidal sand bars. Journal of Sedimentary Petrology, 40,
1095–1127.
Middleton, G. V. (ed.), 1965. Primary Sedimentary Structures and
Their Hydrodynamic Interpretation – A Symposium. Tulsa: Society of Economic Paleontologists and Mineralogists. Special publication number, 12.
Pettijohn, F. J., and Potter, P. E., 1964. Atlas and Glossary of Primary Sedimentary Structures. New York: Springer.
Potter, P. E., and Pettijohn, F. J., 1977. Paleocurrents and Basin
Analysis, 2nd edn. New York: Springer.
Reineck, H. E., and Singh, I. B., 1980. Depositional Sedimentary
Environments. New York: Springer.
Reineck, H. E., and Wunderlich, F., 1968. Classification and Origin
of Flaser and Lenticular Bedding. Sedimentology. New York:
Wiley.
Terwindt, J. H. J., 1988. Paleo-tidal construction of inshore tidal
depositional environments. In de Boer, P. L., van Gelder, A.,
and Nio, S. D. (eds.), Tide-Influenced Sedimentary Environments and Facies. Dordrecht: D. Reidel Publishing Company,
pp. 233–264.
SEICHE
Murat Aksel
Civil Engineering Department, Istanbul Kultur University
Atakoy Campus, Istanbul, Turkey
Synonyms
Eagre; Sea swell
Definition
A seiche is a stationary wave oscillation that causes water
surface oscillations in any period and height under the
effects of different forces such as an earthquake, wind,
barometric pressure, and tide. It was initially described
by the Swiss hydrologist François-Alphonse Forel in
1890, who made the first scientific observations in Lake
Geneva, Switzerland (Darwin, 1898).
Description
The period of a seiche varies from a few minutes to
an hour or more. Wind is the most common seiche producing force, causing water surface heaves against the
downwind shore. Windbreaks cause water surface
oscillation. The period of a seiche is calculated using
Merian’s formula:
T ¼
1
n
2L
ffiffiffiffiffi
gd
p
ð1Þ
where T is the period of the seiche, n is the number of
the nodes of seiche, L is the mean length of the basin,
d is the mean depth, and g is the acceleration of gravity
(Chow, 1964).
Bibliography
Chow, V. T., 1964. Handbook of Applied Hydrology. New York:
McGraw-Hill.
Darwin, G. H., 1898. The Tides and Kindred Phenomena in the
Solar System. New York: Houghton, Mifflin and Company.
Tver, D. F., 1979. Ocean and Marine Dictionary. Ithaca: Cornell
Maritime Pr./Tidewater Publications.
SHANNON-WEAVER DIVERSITY INDEX
Selene Ortiz-Burgos
Facultad de Estudios Superiores Zaragoza, Universidad
Nacional Autónoma de México (UNAM), Delegación
Iztapalapa, DF, México
Synonyms
Shannon index; Shannon information index; ShannonWiener index
Definition
The Shannon-Weaver diversity index is based on communication theory. The uncertainty is measured by the Shannon Function “H
0 .” This term is the measure
corresponding to the entropy concept defined by
H
0
¼ À
X n
n¼1
pi
à ln p i
ð
Þ
ð1Þ
where H
0 is the diversity index, p i is the proportion of each
species in the sample, and ln p i is the natural logarithm of
this proportion (Shannon and Weaver, 1949; Spellerberg
and Fedor, 2003; Magurran, 2004).
Description
The Shannon-Weaver diversity index is one widely used
index for comparing diversity between various habitats
(Clarke and Warwick, 2001). It assumes that individuals
are randomly sampled from an independent large population, and all the species are represented in the sample
(Shannon and Weaver, 1949). The value of the ShannonWeaver diversity index usually ranges from 1.5 to 3.5
and only rarely exceeds 4.5.
The principal objective of a diversity index is to obtain
a quantitative estimate of biological variability that can be
used to compare biological entities in space or in time.
This index takes into account two different aspects that
contribute to the concept of diversity in a community: species richness and evenness.
Bibliography
Clarke, K. R., and Warwick, R. M., 2001. Changes in Marine Communities: An Approach to Statistical Analysis and Interpretation,
2nd edn. Plymouth: PRIMER-E.
Magurran, A., 2004. Measuring Biological Diversity. Oxford:
Blackwell.
572
SEICHE