density of 500 m between points or higher were added
using the remove-restore method (e.g., Smith and
Sandwell, 1997; Hell and Jakobsson, 2011).
IBCAO printed map
In 2004, a printed map at a scale of 1:6,000,000 was
published based on the IBCAO Version 1.0 DBM. Based
on a shaded relief generated from the DBM and overlaid
depth contours, this map portrayed the shape of the Arctic
Ocean seafloor north of 64
N. A polar stereographic map
projection was used with the true scale set at 75
N and the
WGS 84 horizontal datum. The map limit, scale, and projection were taken from the GEBCO Arctic Ocean Sheet
5.17 published in 1979 (Johnson et al., 1979).
Bibliography
Hell, B., and Jakobsson, M., 2011. Gridding heterogeneous bathymetric data sets with stacked continuous curvature splines in tension. Marine Geophysical Research, 32, 493–501.
Jakobsson, M., and IBCAO Editorial Board Members, 2001.
Improvement to the International Bathymetric Chart of the Arctic Ocean (IBCAO): updating the data base and the grid model.
In Union, A. G. (ed.), American Geophysical Union Fall Meeting. San Francisco: EOS Transactions, pp. OS11B–OS0371B.
Jakobsson, M., Cherkis, N., Woodward, J., Macnab, R., and
Coakley, B., 2000. New grid of Arctic bathymetry aids scientists
and mapmakers. EOS, Transactions American Geophysical
Union, 81, 89, 93, 96.
Jakobsson, M., Macnab, R., Mayer, L., Anderson, R., Edwards, M.,
Hatzky, J., Schenke, H. W., and Johnson, P., 2008. An improved
bathymetric portrayal of the Arctic Ocean: implications for
ocean modeling and geological, geophysical and oceanographic
analyses. Geophysical Research Letters, 35, L07602.
Jakobsson, M., Mayer, L., Coakley, B., Dowdeswell, J. A., Forbes, S.,
Fridman, B., Hodnesdal, H., Noormets, R., Pedersen, R., Rebesco,
M., Schenke, H. W., Zarayskaya, Y., Accettella, D., Armstrong, A.,
Anderson, R. M., Bienhoff, P., Camerlenghi, A., Church, I.,
Edwards, M., Gardner, J. V., Hall, J. K., Hell, B., Hestvik, O.,
Kristoffersen, Y., Marcussen, C., Mohammad, R., Mosher, D.,
Nghiem, S. V., Pedrosa, M. T., Travaglini, P. G., and Weatherall,
P., 2012. The International Bathymetric Chart of the Arctic Ocean
(IBCAO) version 3.0. Geophysical Research Letters, 39, L12609.
Johnson, G. L., Monahan, D., Grönlie, G., and Sobczak, L., 1979.
Sheet 5.17. In Canadian Hydrographic Service, O (ed.), General
Bathymetric Chart of the Oceans (GEBCO), 5th edn. Ottawa:
Canadian Hydrographic Service.
Macnab, R., and Grikurov, G., 1997. Report: Arctic Bathymetry
Workshop. St. Petersburg: Institute for Geology and Mineral
Resources of the Ocean (VNIIOkeangeologia), p. 38.
Smith, W. H. F., and Sandwell, D. T., 1997. Global seafloor topography from satellite altimetry and ship depth soundings. Science,
277, 1957–1962.
Smith, W. H. F., and Wessel, P., 1990. Gridding with continuous
curvature splines in tension. Geophysics, 55, 293–305.
Wessel, P., and Smith, W. H. F., 1991. Free software helps map and
display data. EOS Transactions, American Geophysical Union,
72, 441, 445–446.
Cross-references
Ocean Margin Systems
Plate Tectonics
INTRAOCEANIC SUBDUCTION ZONE
Hayato Ueda
Department of Geology, Niigata University, Nishi-ku,
Niigata, Japan
Synonyms
Oceanic subduction zone
Definition
Intraoceanic subduction zone. A subduction zone developed beneath the leading edge of an oceanic lithosphere.
Introduction
Intraoceanic subduction zones were developed beneath
leading edges of oceanic crusts. Although the accompanied volcanic arcs (intraoceanic island arcs) have thickened crusts compared with normal oceanic crusts, they
are still immature and thinner than continental crusts. It
is thus distinguished from continental arcs (Active Continental Margins). An intraoceanic subduction zone is associated with an oceanic basin, i.e., back-arc basin, behind
the volcanic arc. Continental island arcs such as Northeast
Japan and Kurile arcs are also accompanied by back-arc
basins (marginal basins) at least partly of oceanic crusts.
These arcs developed upon old continental crusts split
from continents behind and can also be distinguished from
intraoceanic arcs consisting essentially of arc magmatic
rocks developed in intraoceanic settings.
Modern intraoceanic subduction zones cluster in the
western Pacific and also occur in the western Atlantic
(Figure 1). They contrast with eastern Pacific margins
bounded almost entirely by continental subduction zones.
Among them, the Izu-Bonin-Mariana, Lesser Antilles
(Barbados), and South Sandwich subduction zones developed along margins of independent small oceanic plates
mechanically decoupled with continents. The TongaKermadec and Aleutian subduction zones are situated
along margins of well-developed oceanic basin connected
with continents. In Southeast Asia to Melanesia regions,
shorter subduction zones are complicatedly arranged.
Some arcs are bounded by subduction zones of opposite
polarities or being switched from one to another (e.g.,
Philippine and Solomon arcs). There are also many indistinct trenches with poorly developed volcanic arcs and
abandoned trenches in these areas.
Intraoceanic subduction zones are the major sites for
descending of the Earth’s surface materials (oceanic crust,
sediments, and fluids), seismic and volcanic activities,
hydrothermalism, and growth of sialic continental crusts.
They could be modern analogues for origins of ophiolites
on land and can also give hints to consider tectonics and
environments in the early Earth’s history when continental
crusts had not yet been well-developed.
INTRAOCEANIC SUBDUCTION ZONE
367
using the remove-restore method (e.g., Smith and
Sandwell, 1997; Hell and Jakobsson, 2011).
IBCAO printed map
In 2004, a printed map at a scale of 1:6,000,000 was
published based on the IBCAO Version 1.0 DBM. Based
on a shaded relief generated from the DBM and overlaid
depth contours, this map portrayed the shape of the Arctic
Ocean seafloor north of 64
N. A polar stereographic map
projection was used with the true scale set at 75
N and the
WGS 84 horizontal datum. The map limit, scale, and projection were taken from the GEBCO Arctic Ocean Sheet
5.17 published in 1979 (Johnson et al., 1979).
Bibliography
Hell, B., and Jakobsson, M., 2011. Gridding heterogeneous bathymetric data sets with stacked continuous curvature splines in tension. Marine Geophysical Research, 32, 493–501.
Jakobsson, M., and IBCAO Editorial Board Members, 2001.
Improvement to the International Bathymetric Chart of the Arctic Ocean (IBCAO): updating the data base and the grid model.
In Union, A. G. (ed.), American Geophysical Union Fall Meeting. San Francisco: EOS Transactions, pp. OS11B–OS0371B.
Jakobsson, M., Cherkis, N., Woodward, J., Macnab, R., and
Coakley, B., 2000. New grid of Arctic bathymetry aids scientists
and mapmakers. EOS, Transactions American Geophysical
Union, 81, 89, 93, 96.
Jakobsson, M., Macnab, R., Mayer, L., Anderson, R., Edwards, M.,
Hatzky, J., Schenke, H. W., and Johnson, P., 2008. An improved
bathymetric portrayal of the Arctic Ocean: implications for
ocean modeling and geological, geophysical and oceanographic
analyses. Geophysical Research Letters, 35, L07602.
Jakobsson, M., Mayer, L., Coakley, B., Dowdeswell, J. A., Forbes, S.,
Fridman, B., Hodnesdal, H., Noormets, R., Pedersen, R., Rebesco,
M., Schenke, H. W., Zarayskaya, Y., Accettella, D., Armstrong, A.,
Anderson, R. M., Bienhoff, P., Camerlenghi, A., Church, I.,
Edwards, M., Gardner, J. V., Hall, J. K., Hell, B., Hestvik, O.,
Kristoffersen, Y., Marcussen, C., Mohammad, R., Mosher, D.,
Nghiem, S. V., Pedrosa, M. T., Travaglini, P. G., and Weatherall,
P., 2012. The International Bathymetric Chart of the Arctic Ocean
(IBCAO) version 3.0. Geophysical Research Letters, 39, L12609.
Johnson, G. L., Monahan, D., Grönlie, G., and Sobczak, L., 1979.
Sheet 5.17. In Canadian Hydrographic Service, O (ed.), General
Bathymetric Chart of the Oceans (GEBCO), 5th edn. Ottawa:
Canadian Hydrographic Service.
Macnab, R., and Grikurov, G., 1997. Report: Arctic Bathymetry
Workshop. St. Petersburg: Institute for Geology and Mineral
Resources of the Ocean (VNIIOkeangeologia), p. 38.
Smith, W. H. F., and Sandwell, D. T., 1997. Global seafloor topography from satellite altimetry and ship depth soundings. Science,
277, 1957–1962.
Smith, W. H. F., and Wessel, P., 1990. Gridding with continuous
curvature splines in tension. Geophysics, 55, 293–305.
Wessel, P., and Smith, W. H. F., 1991. Free software helps map and
display data. EOS Transactions, American Geophysical Union,
72, 441, 445–446.
Cross-references
Ocean Margin Systems
Plate Tectonics
INTRAOCEANIC SUBDUCTION ZONE
Hayato Ueda
Department of Geology, Niigata University, Nishi-ku,
Niigata, Japan
Synonyms
Oceanic subduction zone
Definition
Intraoceanic subduction zone. A subduction zone developed beneath the leading edge of an oceanic lithosphere.
Introduction
Intraoceanic subduction zones were developed beneath
leading edges of oceanic crusts. Although the accompanied volcanic arcs (intraoceanic island arcs) have thickened crusts compared with normal oceanic crusts, they
are still immature and thinner than continental crusts. It
is thus distinguished from continental arcs (Active Continental Margins). An intraoceanic subduction zone is associated with an oceanic basin, i.e., back-arc basin, behind
the volcanic arc. Continental island arcs such as Northeast
Japan and Kurile arcs are also accompanied by back-arc
basins (marginal basins) at least partly of oceanic crusts.
These arcs developed upon old continental crusts split
from continents behind and can also be distinguished from
intraoceanic arcs consisting essentially of arc magmatic
rocks developed in intraoceanic settings.
Modern intraoceanic subduction zones cluster in the
western Pacific and also occur in the western Atlantic
(Figure 1). They contrast with eastern Pacific margins
bounded almost entirely by continental subduction zones.
Among them, the Izu-Bonin-Mariana, Lesser Antilles
(Barbados), and South Sandwich subduction zones developed along margins of independent small oceanic plates
mechanically decoupled with continents. The TongaKermadec and Aleutian subduction zones are situated
along margins of well-developed oceanic basin connected
with continents. In Southeast Asia to Melanesia regions,
shorter subduction zones are complicatedly arranged.
Some arcs are bounded by subduction zones of opposite
polarities or being switched from one to another (e.g.,
Philippine and Solomon arcs). There are also many indistinct trenches with poorly developed volcanic arcs and
abandoned trenches in these areas.
Intraoceanic subduction zones are the major sites for
descending of the Earth’s surface materials (oceanic crust,
sediments, and fluids), seismic and volcanic activities,
hydrothermalism, and growth of sialic continental crusts.
They could be modern analogues for origins of ophiolites
on land and can also give hints to consider tectonics and
environments in the early Earth’s history when continental
crusts had not yet been well-developed.
INTRAOCEANIC SUBDUCTION ZONE
367