Continental Spreading Boundaries
Seismotectonics
Peter Matheny
September 29, 2016
1/7
Contents
I
Spreading boundaries around the world
I
East African Rift (EAR) history
I
Regional Setting
I
Current Best Model
I
What’s Going on Underneath?
2/7
Contents
I
Spreading boundaries around the world
I
East African Rift (EAR) history
I
Regional Setting
I
Current Best Model
I
What’s Going on Underneath?
2/7
Contents
I
Spreading boundaries around the world
I
East African Rift (EAR) history
I
Regional Setting
I
Current Best Model
I
What’s Going on Underneath?
2/7
Contents
I
Spreading boundaries around the world
I
East African Rift (EAR) history
I
Regional Setting
I
Current Best Model
I
What’s Going on Underneath?
2/7
Contents
I
Spreading boundaries around the world
I
East African Rift (EAR) history
I
Regional Setting
I
Current Best Model
I
What’s Going on Underneath?
2/7
Continental Spreading Boundaries
I
West Antarctic Rift
I
Baikal Rift Zone
I
Great Rift Valley
I
Basin and Range?
KON
South Orkney Is
Signy (UK)
G HÅK ON VI
I H
A
BULIS E N
FIM
V
S
bulheimen
Fim
COATS LAND
LA
ND
LA
s
tn
w o r th
M
Thiel
Mtns
ELLSWORTH LAND
AM ERY
IC E SH ELF
a
PRINCESS
ELIZABETH
LAND
South Pole
Amundsen-Scott (USA)
LF
ar
WILHELM II
LAND
ic
Queen
Elizabeth
Range
QUEEN MARY
LAND
Subglacial
Lake Vostok
M
00
30
o
Queen
Alexandra
Range
E
IC
OR
CT
VI
H
IA LAND
E
ROSS SEA
WILKES
LAND
Dome
Circe
ns
SH
ROSS
ICE
SHELF
McMurdo
(USA)
2000
TZ
MARIE
BYRD
LAND
ta i
GE
Executive
Committee
Range
EL
F
90°E
Davis
Sea
ct
un
SHACKLETON
ICE
SHELF
R
OATES LAND
GEORGE V
LAND
TERRE
ADÉLIE
N
Dumont d’Urville
Sea
C
Balleny Is
E
6°S0
T
S O U
nt
Queen
Maud
Mtns
Mt Erebus
O
Prydz
Bay
LAND
Dome
Argus
400
0
O C E
A N
Whitmore
Mtns
WEST
ANTARCTICA
AMUNDSEN
SEA
ns
P rince C harles Mt
EAST ANTARCTICA
s
ns
Peter I Øy
MACROBERTSON
Tra
Vinson
Massif
4892m
E lls
SEA
ABBOT ICE S HE
90°W
Scott Mtns
KEMP LAND
Dome
Fuji
(Valkyrie)
Shackleton
Range
n
Mt
ola
P ensac
RONNE
ICE
SHELF
R
Alexander I.
FILCHNER
ICE
Berkner
SHELF
Island
S
Rothera (UK)
BELLINGSHAUSEN
ENDERBY
LAND
Halley (UK)
SEA
NIN
SU
PA
LM
E
07°
PE
R N
H E
ND
LA
LARSEN
ICE SHELF
Adelaide I.
80
°S
TIC
Anvers I.
Th
or
sh
avn
heine
T
AM
GRAH
Is
Palmer (USA)
BRUNT
ICE
SHELF
WEDDELL
U
C
AR
ANT
Shetland
O
DRONNING MAUD
LAND
South
180°
A
N
0
1000
2000
Km
0
200
400
600
800 1000
Miles
3/7
Continental Spreading Boundaries
I
West Antarctic Rift
I
Baikal Rift Zone
I
Great Rift Valley
I
Basin and Range?
3/7
Continental Spreading Boundaries
I
West Antarctic Rift
I
Baikal Rift Zone
I
Great Rift Valley
I
Basin and Range?
3/7
Continental Spreading Boundaries
I
West Antarctic Rift
I
Baikal Rift Zone
I
Great Rift Valley
I
Basin and Range?
3/7
History of EAR
I
I
I
Oceanic spreading rates from the Red Sea and Southwest
Indian Ridge (Jestin et. al., 1999)
Addition of GPS angular velocities and slip vectors (Calais et.
al., 2006)
More GPS angular velocities (Saria et. al., 2014)
4/7
History of EAR
I
I
I
Oceanic spreading rates from the Red Sea and Southwest
Indian Ridge (Jestin et. al., 1999)
Addition of GPS angular velocities and slip vectors (Calais et.
al., 2006)
More GPS angular velocities (Saria et. al., 2014)
4/7
History of EAR
I
I
I
Oceanic spreading rates from the Red Sea and Southwest
Indian Ridge (Jestin et. al., 1999)
Addition of GPS angular velocities and slip vectors (Calais et.
al., 2006)
More GPS angular velocities (Saria et. al., 2014)
4/7
Regional Setting
I
African superswell
supporting topography in
the region (Ritsema et. al.,
1998)
I
Western branch
I
Eastern branch
5/7
Regional Setting
I
African superswell
supporting topography in
the region (Ritsema et. al.,
1998)
I
Western branch
I
Eastern branch
5/7
Regional Setting
I
African superswell
supporting topography in
the region (Ritsema et. al.,
1998)
I
Western branch
I
Eastern branch
5/7
Current Best Fit Model
6/7
What’s Going on Underneath?
7/7
What’s Going on Underneath?
7/7