GEOCHEMISTRY GEOPHYSICS GEOSYSTEMS, VOL. 4, NO. 3, 1027, doi:10.1029/2001GC000252, 2003

An updated digital model of plate boundaries

Peter Bird
Department of Earth and Space Sciences, University of California
Los Angeles, California, USA

A global set of present plate boundaries on the Earth is presented in digital form. Most come from sources in the literature. A few boundaries are newly interpreted from topography, volcanism, and/or seismicity, taking into account relative plate velocities from magnetic anomalies, moment tensor solutions, and/or geodesy. In addition to the 14 large plates whose motion was described by the NUVEL-1A poles (Africa, Antarctica, Arabia, Australia, Caribbean, Cocos, Eurasia, India, Juan de Fuca, Nazca, North America, Pacific, Philippine Sea, South America), model PB2002 includes 38 small plates (Okhotsk, Amur, Yangtze, Okinawa, Sunda, Burma, Molucca Sea, Banda Sea, Timor, Birds Head, Maoke, Caroline, Mariana, North Bismarck, Manus, South Bismarck, Solomon Sea, Woodlark, New Hebrides, Conway Reef, Balmoral Reef, Futuna, Niuafo'ou, Tonga, Kermadec, Rivera, Galapagos, Easter, Juan Fernandez, Panama, North Andes, Altiplano, Shetland, Scotia, Sandwich, Aegean Sea, Anatolia, Somalia), for a total of 52 plates. No attempt is made to divide the Alps-Persia-Tibet mountain belt, the Philippine Islands, the Peruvian Andes, the Sierras Pampeanas, or the California-Nevada zone of dextral transtension into plates; instead, they are designated as orogens in which this plate model is not expected to be accurate. The cumulative-number/area distribution for this model follows a power law for plates with areas between 0.002 and 1 steradian. Departure from this scaling at the small-plate end suggests that future work is very likely to define more very small plates within the orogens. The model is presented in four digital files: a set of plate boundary segments; a set of plate outlines; a set of outlines of the orogens; and a table of characteristics of each digitization step along plate boundaries, including estimated relative velocity vector and classification into one of 7 types (continental convergence zone, continental transform fault, continental rift, oceanic spreading ridge, oceanic transform fault, oceanic convergent boundary, subduction zone). Total length, mean velocity, and total rate of area production/destruction are computed for each class; the global rate of area production and destruction is 0.108 m2/s, which is higher than in previous models because of the incorporation of back-arc spreading.

Description of table

Plate boundary classes and class numbers

Plate Identifiers

Identifier Plate Name
AF	Africa
AM	Amur
AN	Antarctica
AP	Altiplano
AR	Arabia
AS	Aegean Sea
AT	Anatolia
AU	Australia
BH	Birds Head
BR	Balmoral Reef
BS	Banda Sea
BU	Burma
CA	Caribbean
CL	Caroline
CO	Cocos
CR	Conway Reef
EA	Easter
EU	Eurasia
FT	Futuna
GP	Galapagos
IN	India
JF	Juan de Fuca
JZ	Juan Fernandez
KE	Kermadec
MA	Mariana
MN	Manus
MO	Maoke
MS	Molucca Sea
NA	North America
NB	North Bismarck
ND	North Andes
NH	New	Hebrides
NI	NiuafoĠou
NZ	Nazca
OK	Okhotsk
ON	Okinawa
PA	Pacific
PM	Panama
PS	Philippine Sea
RI	Rivera
SA	South America
SB	South Bismarck
SC	Scotia
SL	Shetland
SO	Somalia
SS	Solomon
SU	Sunda
SW	Sandwich
TI	Timor
TO	Tonga
WL	Woodlark
YA	Yangtze