Summary

Examination of more than 100 fault plane solutions for earthquakes within the Alpide belt between the Mid-Atlantic ridge and Eastern Iran shows that the deformation at present occurring is the result of small continental plates moving away from Eastern Turkey and Western Iran. This pattern of movement avoids thickening the continental crust over much of Turkey by consuming the Eastern Mediterranean sea floor instead. The rates of relative motion of two of the small plates involved, the Aegean and the Turkish plates, are estimated, but are only within perhaps 50 per cent of the true values. These estimates are then used to reconstruct the geometry of the Mediterranean 10 million years ago. The principal difference from the present geometry is the smooth curved coast which then formed the southern coast of Yugoslavia, Greece and Turkey. This coast has since been distorted by the motion of the two small plates. Similar complications have probably been common in older mountain belts, and therefore local geological features may not have been formed by the motion between major plates.

A curious feature of several of the large shocks for which fault plane solutions could be obtained for the main shock and one major after-shock was that the two often had different mechanisms.

References

Allen
C. R.
,
1965
.
Transcurrent faults in continental areas
,
Phil. Trans. R. Soc.
 ,
258
,
82
.
Allen
C. R.
,
1969
.
Active faulting in northern Turkey
 ,
Division of Geological Sciences, Contribution No. 1577, California Institute of Technology
,
Pasadena, California
.
Ambraseys
N. N.
,
1963
.
The Buyin-Zara (Iran) earthquake of September 1962: a field report
,
Bull. seism. Soc. Am.
 ,
53
,
705
.
Ambraseys
N. N.
,
1968
.
Early earthquakes in north-central Iran
,
Bull. seism. Soc. Am.
 ,
58
,
485
.
Ambraseys
N. N.
,
1971
.
On the value of historical records of earthquakes
,
Nature
 ,
232
,
375
.
Ambraseys
N. N.
Tchalenko
J. S.
,
1969
.
The Dasht-e-Bayaz (Iran) earthquake of 1968 August 31: a field report
,
Bull. seism. Soc. Am.
 ,
59
,
1751
.
Ambraseys
N. N.
Tchalenko
J. S.
,
1970
.
The Gediz (Turkey) earthquake of 1970 March 28
,
Nature
 ,
227
,
592
.
Ambraseys
N. N.
Zatopek
A.
,
1968
.
The Varto Ustukran (Anatolia) earthquake of 1966 August 19: a summary of a field report
,
Bull. seism. Soc. Am.
 ,
58
,
47
.
Ambraseys
N. N.
Zatopek
A.
,
1969
.
The Mudurnu Valley, West Anatolia, Turkey, earthquake of 1967 July 22
,
Bull. seism. Soc. Am.
 ,
59
,
521
.
Anderson
E. M
,
1951
.
The dynamics of faulting
 ,
Oliver and Boyd
,
Edinburgh
.
Aubouin
J.
Brunn
J. H.
Celet
P.
Dercourt
J.
Godfriauz
I.
Mercier
J.
,
1963
.
Esquisse de la geologie de la Grece
,
Fallot
 
Volume II
,
583
610
.
Balakina
L. M.
Vvedenskaya
A. V.
Misharina
L. A.
Shirokova
E. I.
,
1967
.
The stress state in earthquake foci and the elastic stress field of the earth
,
Izv. Acad. Sci. USSR, Geophys. Ser., 1967
  (
6
),
333
.
Banghar
A. R.
Sykes
L. R.
,
1969
.
Focal mechanisms of earthquakes in the Indian Ocean and adjacent regions
,
J. geophys. Res.
 ,
74
,
632
.
Barazangi
M.
Dorman
J.
,
1969
.
World seismicity maps compiled from ESSA coast and geodetic survey epicenter data, 1961–1967
,
Bull. seism. Soc. Am.
 ,
59
,
369
.
Bayer
K. C.
Heuckroth
L. E.
Karim
R. A.
,
1969
.
An investigation of the Dasht-e-Bayaz, Iran, earthquake of 1968 August 31
,
Bull. seism. Soc. Am.
 ,
59
,
1793
.
Ben-Menahem
A.
,
1961
.
Radiation of seismic surface waves from finite moving sources
,
Bull. seism. Soc. Am.
 ,
51
,
401
.
Brune
J. N.
,
1968
.
Seismic moment, seismicity and rate of slip along major fault zones
,
J. geophys. Res.
 ,
73
,
777
.
Bune
V. I.
Vvedenskaya
N. A.
Gorbunova
I. V.
Kondorskava
N. V.
Landyreva
N. S.
Fedorova
I. V.
,
1970
.
Correlation of MLN and mpv by data of the network of seismic stations of the USSR
,
Geophys. J. R. astr. Soc.
 ,
19
,
533
.
Canitez
N.
,
1969
.
The focal mechanisms in Iran and their relations to tectonics
,
Pure appl. Geophys.
 ,
75
,
76
.
Canitez
N.
Ucer
S. B.
,
1967
.
Computer determinations for the fault-plane solutions in and near Anatolia
,
Tectonophysics
 ,
4
,
235
.
Canitez
N.
Ucer
S. B.
,
1967
.
A catalogue of focal mechanism diagrams for Turkey and adjoining areas
,
ITU Arz. Fizigi Enstitusu
 ,
25
.
Davies
D.
McKenzie
D. P.
,
1969
.
Seismic travel-time residuals and plates
,
Geophys. J. R. astr. Soc.
 ,
18
,
51
.
Davison
C.
,
1936
.
Great earthquakes
 ,
Thomas Murby
,
London
.
Dewey
J. F.
Bird
J. M.
,
1971
.
Origin and emplacement of the ophiolite suite: Appalachian ophiolites in Newfoundland
,
J. geophys. Res.
 ,
76
,
3179
.
Dickinson
W. R.
,
1970
.
Relation of andesites, granites and derivative sandstones to Arc-Trench tectonics
,
Rev. Geophys.
 ,
8
,
813
.
Di Filippo
D.
,
1950
.
Sulla Rappresentazione in Superficie della natura dinamica di una Scossa All'Ipocentro
,
Ann. Geof.
 ,
3
,
263
.
Di Filippo
D.
Marcelli
L.
,
1951
.
Uno Studio del terremoto de Gran Sasso d'Italia del 1950 Septembre 5
,
Ann. Geof
 ,
4
,
213
.
Di Filippo
D.
Marcelli
L.
,
1954
.
Uno Studio Sul Terremoto di Cefalonia (del 1953 Augosto 12) con Particolare Reguardo alla Natura fisica Della Scossa All'Ipocentro
,
Ann. Geof
 ,
7
,
547
.
Di Filippo
D.
Peronaci
F.
,
1959
.
Natura fisica della scossa all'Ipocentro di alcuni terremoti profundi nel Mediteranno
,
Ann. Geof
 ,
12
,
549
.
Di Filippo
D.
Peronaci
F.
,
1961
.
Struttura della crosta terrestre nelle Prealpi Lombardo-Venete quale risulta della studio del terremoto del Garda del 1960 Febbraio 19
,
Ann. Geof.
 ,
14
,
409
.
Di Filippo
D.
Peronaci
F.
,
1962
.
Terremoti di frattura e relazioni con la tettonica nelle Alpi Orientali
,
Ann. Geof
 ,
15
,
195
.
Di Filippo
D.
Peronaci
F.
,
1962
.
Contributo alla tectonica delle Alpi Dinariche
,
Ann. Geof
 ,
15
,
379
.
Di Filippo
D.
Peronaci
F.
,
1963
.
Indagine preliminare della natura fisica del fenomeno the la originato il periodo sismico irpino dell' Augosto 1962
,
Ann. Geof
 ,
16
,
625
.
Di Filippo
D.
Peronaci
F.
,
1964
.
La sismicita del ‘Campo fagliato’ dell' Aterno
,
Ann. Geof.
 ,
17
,
195
.
Diligan
H.
Hagiwara
T.
,
1955
.
Le tremblement de terre de Yenice 1953 mars 18
,
Pub,. Bureau centre intern. Seism. Trav. Sci., A
 ,
19
,
287
.
Division of Geological and Planetary Sciences
,
California Institute of Technology, 1971. Preliminary seismological and geological studies of the San Fernando California, earthquake of 1971 February 9
,
Bull. seism. Soc. Am.
 ,
61
,
491
.
Elsasser
W. M.
,
1967
.
Convection and stress propagation in the Upper Mantle
,
Princeton Univ. Tech. Report
 ,
5
.
Ergin
K.
,
1966
.
On the epicentre map of Turkey and surrounding area
,
Turk. Jeol. Kur. Bult.
 ,
10
,
122
.
Falcon
N. L.
,
1967
.
The geology of the north-eastern margin of the Arabian basement shield
,
Advancement in Science
 ,
24
,
31
.
Fitch
T. J.
,
1970
.
Earthquake mechanisms in the Himalayan, Burmese, and Andaman regions and continental tectonics in central Asia
,
J. geophys. Res.
 ,
75
,
2699
.
Florensov
N. A.
Solonenko
V. P.
,
1963
.
The Gobi-Altai earthquake
,
Akademii Nauk SSSR
 
(Engl. transl. available from the U.S. Department of Commerce, 1965)
.
Ganser
A.
,
1969
.
The large earthquakes of Iran and their geological frame
,
Eclogae geol. Helv.
 ,
62
,
443
.
Galanopoulos
A. G.
,
1967
.
The seismotectonic regime in Greece
,
Ann. Geof.
 ,
20
,
109
.
Galanopoulos
A. G.
Delibasis
N. D.
,
1965
.
Seismic activity in the Cyprus area
,
Proc. Athens Acad.
 ,
40
,
387
.
Gutenberg
B.
Richter
C. F.
,
1954
.
Seismicity of the Earth
 ,
Princeton University Press
,
Princeton
.
Hamilton
R. M.
Gale
A. W.
,
1968
.
Seismicity and structure of North Island, New Zealand
,
J. geophys. Res.
 ,
73
,
3859
.
Hill
M. L.
Dibblee
T. W.
,
1953
.
San Andreas, Garlock and Big Pine faults, California
,
Bull. geol. Soc. Am.
 ,
64
,
443
.
Hodgson
J. H.
,
1957
.
Nature of faulting in large earthquakes
,
Bull. geol. Soc. Am.
 ,
68
.
611
Hodgson
J. H.
Cock
J. I.
,
1956
.
Direction of faulting in the deep focus Spanish earthquake of 1954 March 29
,
Tellus
 ,
8
,
321
.
Hodgson
J. H.
Wickens
A. J.
,
1965
.
Computer-determined P-Nodal solutions for larger earthquakes of 1959–1962
,
Publ. Dom. Obs., Ottawa
 ,
31
,
123
.
Honda
H.
,
1962
.
Earthquake mechanism and seismic waves
,
J. Phys. Earth (Tokyo)
 ,
10
,
1
.
Hsü
K.
Schlanger
S. O.
,
1971
.
Ultrahelvetic flysch sedimentation and deformation related to plate tectonics
,
Bull. geol. Soc. Am.
 ,
82
,
1207
.
Isacks
B. L.
Molnar
P.
,
1971
.
Distribution of stresses in the descending lithosphere from a global survey of focal-mechanism solutions of mantle earthquakes
,
Rev. Geophys
 .
9
,
103
.
Isacks
B. L.
Oliver
J.
Sykes
L. R.
,
1968
.
Seismology and the new global tectonics
J. geophys. Res
 .
73
,
5855
.
Ketin
I.
,
1948
.
Uber die tektonischmechanischen Folgerungen aus den grossen anatolischen Erdbeben des letzten Dezenniums
Geol. Rundschau
 
36
,
77
.
Ketin
I.
,
1966
.
1964 Ekim 6 Manyas Depremi Esnasinda Zeminde Meydana gelen Tansiyon Catlaklari
Turk. Jeol. Kur. Büll
 .
10
,
44
.
Ketin
I.
Roesli
F.
,
1953
.
Makroseismische Untersuchungen über das nordwestanatolische Beben vom 1953 März 18
Eclogae Geol. Helv
 .
46
,
187
.
Krause
D. C.
Watkins
N. D.
,
1970
.
North Atlantic crustal genesis in the vicinity of the Azores
Geophys. J. R. astr. Soc
 .
19
,
261
Le Pichon
X.
,
1968
.
Sea-floor spreading and continental drift
J. geophys. Res.
 ,
73
,
3661
.
Le Pichon
X.
Auzende
J. M.
Pautot
G.
Monti
S.
Francheteau
J.
,
1971
.
Deep sea photographs of an active seismic fault zone near Gibraltar straits
Nature
 ,
230
,
110
.
Lort
J. M.
,
1971
.
The tectonics of the Eastern Mediterranean. a geophysical review
Rev. Geophys.
 ,
9
,
189
.
Maxwell
J. C.
,
1959
.
Turbidite, tectonic and gravity transport, Northern Apennine Mountains, Italy
,
Bull. Am. Assoc. Petrol. Geol.
 ,
43
,
2701
.
McKenzie
D. P.
,
1969
.
Speculations on the causes and consequences of plate motions
,
Geophys. J. R. astr. Soc.
 ,
18
,
1
.
McKenzie
D. P.
,
1969
.
The relation between fault plane solutions for earthquakes and the directions of the principal stresses
,
Bull. seism. Soc. Am.
 ,
59
,
591
.
McKenzie
D. P.
,
1970
.
The plate tectonics of the Mediterranean region
,
Nature
 ,
226
,
239
.
McKenzie
D. P.
Molnar
P.
Davies
D.
,
1970
.
Plate tectonics of the Red Sea and East Africa
,
Nature
 ,
226
,
243
.
McKenzie
D. P.
Morgan
W. J.
,
1969
.
The evolution of triple junctions
,
Nature
 ,
224
,
125
.
McKenzie
D. P.
Parker
R. L.
,
1967
.
The North Pacific: an example of tectonics on a sphere
,
Nature
 .
216
,
1276
.
McKenzie
D.
Sclater
J. G.
,
1971
.
The evolution of the Indian Ocean since the Late Cretaceous
,
Geophys. J. R. astr. Soc.
 ,
24
,
437
.
Munuera
J. M.
,
1965
.
A study of the seismicity on the Peninsula Iberica area, epicentres and frequency
,
Scientific Report No. 6, Inst. Geografico y Catastral, Madrid
 .
National Iranian Oil Company
,
1959
.
Geological Map of Iran Scale 1: 2,500,000
 ,
National Iranian Oil Co.
,
Tehran
.
Neprochnov
Y. P.
,
1968
.
Structure of the Earth's crust of epicontinental seas, Caspian, Black and Mediterranean
,
Can. J. earth Sci.
 ,
5
,
1037
.
Niazi
M.
,
1969
.
Source dynamics of the Dasht-e-Bayaz earthquake of 1968 August 31
,
Bull. seism. Soc. Am.
 ,
59
,
1843
.
Niazi
M.
Basford
J. R.
,
1968
.
Seismicity of Iranian Plateau and Hindu Kush region
,
Bull. seism. Soc. Am.
 ,
58
,
417
.
Nowroozi
A. A.
,
1971
.
Seismo-tectonics of the Persian Plateau
,
Bull. seism. Soc. Am.
 ,
61
,
317
.
Ocal
N.
,
1960
.
Determination of the mechanism of some Anatolian earthquakes
,
Publ. Dom. Obs., Ottawa
 ,
24
,
365
.
Ocal
N.
,
1966
.
Geometrical solutions of fault-plane problem of some of the destructive earthquakes occurred in Anatolia in the period 1938-1955
,
Z. Geophys.
 ,
32
,
293
.
Peronaci
F.
,
1958
.
Sismicita dell'Iran
,
Ann. Geof.
 ,
11
,
55
.
Peronaci
F.
,
1959
.
Contribo alla conoscenza delle caratteristiche sismiche dell'Iran settentrionalle
,
Ann. Geof.
 ,
12
,
523
.
Peterschmitt
E.
,
1956
.
Quelques donnes, nouvelles sur les seismes profonds de la mer tyrrhenienne
.
Ann. Geof.
 ,
9
,
305
.
Pitman
W. C.
Talwani
M.
Heirtzler
J. R.
,
1971
.
Age of the North Atlantic Ocean from magnetic anomalies
,
Earth Planet. Sci. Lett.
 ,
11
,
195
.
Reid
H. F.
,
1914
.
The Lisbon earthquake of 1755 November 1
,
Bull. seism. Soc. Am.
 ,
4
,
53
.
Richter
C. F.
,
1958
.
Elementary Seismology
 ,
W. H. Freeman
,
San Francisco
.
Ritsema
A. R.
,
1967
.
Mechanisms of European earthquakes
,
Tectonophys.
 ,
4
,
247
.
Ritsema
A. R.
,
1969
.
Seismic data of the west Mediterranean and the problem of oceanization
,
Verhand. Kon. Ned. geol. Mijnbouwk. Gen.
 ,
26
,
105
.
Ritsema
A. R.
,
1971
.
Notes on plate tectonics and are movements in the Mediterranean region
,
Comm. Observ. R. de Belgique, Geophys. Ser.
 ,
101
,
22
.
Roman
C.
,
1970
.
Seismicity in Roumania: evidence for the sinking lithosphere
,
Nature
 ,
228
,
1176
.
Rothé
J. P.
,
1955
.
Le tremblement de terre d'Orléansville, et la seismicite de l'Algerie
,
La Nature, Paris, No
 .
3237
,
1
.
Rustanovich
D. N.
Shirokova
E. I.
,
1964
.
Some results of a study of the Askhabad earthquake of 1948
,
Izv. Akad. Nauk. USSR, Ser. Geophiz
 .,
1077
Ryan
W. B. F.
Stanley
D. J.
Hersey
J. B.
Fahiquist
D. A.
Allan
T. D.
,
1970
.
The tectonics and geology of the Mediterranean
,
The Sea
 , Vol.
4
, p.
387
, ed
Maxwell
A. E.
,
Wiley-Interscience
.
Savage
J. C.
,
1971
.
A theory of creep waves propagating along a transform fault
,
J. geophys. Res.
 ,
76
,
1954
.
Shirokova
E. I.
,
1962
.
Stresses effective in earthquake foci in the Caucasus and adjacent districts
,
Izv. Akad. Nauk. USSR, Ser. Geophiz.
 ,
10
,
809
.
Shirokova
E. I.
,
1967
.
General features in the orientation of principal stresses in earthquake foci in the Mediterranean-Asian seismic belt
,
Izv. Acad. Nauk. USSR, Ser. Geophiz.
 ,
1
,
12
.
Smith
A. G.
,
1971
.
Alpine deformation and the oceanic areas of the Tethys, Mediterranean and Atlantic
,
Bull. geol. Soc. Am.
 ,
82
,
2039
.
Stauder
W.
,
1962
.
The focal mechanism of earthquakes
,
Adv. Geophys.
 ,
9
,
1
.
Stauder
W.
,
1968
.
Mechanism of the Rat Island earthquake sequence of 1965 February 4, with relation to island arcs and sea-floor spreading
,
J. geophys. Res.
 ,
73
,
3847
.
Stevens
A. E.
Hodgson
J. H.
,
1968
.
A study of P-Nodal solutions (1922–1962) in the Wickens-Hodgson Catalogue
,
Bull. seism. Soc. Am.
 ,
58
,
1071
.
Sykes
L. R.
,
1967
.
Mechanism of earthquakes and nature of faulting on the Mid-Oceanic ridges
,
J. geophys. Res.
 ,
72
,
2131
.
Times Atlas of the World
,
1968
.
Times Newspapers Ltd
,
London.
.
Trümpy
R.
,
1960
.
Palaeotectonic evolution of the Central and Western Alps
,
Bull. geol. Soc. Am.
 ,
71
,
843
.
Udias
A.
,
1967
.
The focal mechanism of earthquakes in the southern coast of the Iberian Peninsula
,
Tectonophys.
 ,
4
,
229
.
Udias
A.
,
1971
.
Source parameters of earthquakes from spectra of Rayleigh waves
,
Geophys. J. R. astr. Soc.
 ,
22
,
353
.
Udias
A.
Arroyo
A. L.
,
1970
.
Body and surface wave study of source parameters of the 1964 March 15 Spanish earthquake
,
Tectonophys.
 ,
9
,
323
.
Voo
R.
Zijderveld
J. D. A.
,
1969
.
Paleomagnetism in the Western Mediterranean Sea
,
Verhand. Kon. Ned. geol. Mijnbouwk. Gen.
 ,
26
,
121
.
Vogt
P. R.
Higgs
R. H.
,
1969
.
An aeromagnetic survey of the Eastern Mediterranean Sea and its interpretation
,
Earth Planet. Sci. Lett.
 ,
5
,
439
.
Wallace
R. E.
,
1968
.
Earthquake of 1966 August 19 Varto area, Eastern Turkey
,
Bull. seism. Soc. Am.
 ,
58
,
11
.
Washington
H. S.
,
1906
.
Roman Comagnetic region
,
Carnegie Inst., Washington, Publ. No
 .
57
.
Washington
H. S.
,
1926
.
Santorini eruption of 1925
,
Bull. geol. Soc. Am.
 ,
37
,
349
.
Wellman
H. H.
,
1966
.
Active wrench faults of Iran, Afghanistan and Pakistan
,
Geol. Rundschau
 ,
55
,
716
.
Wickens
A. J.
Hodgson
J. H.
,
1967
.
Computer re-evaluation of earthquake mechanism solutions 1922–1962
,
Publ. Dom. Obs. Ottawa
 ,
33
,
1
.
Wilson
J. T.
,
1965
.
A new class of faults and their bearing on continental drift
,
Nature
 ,
207
,
343
.