Lake Baikal

lameubiquityMécanique

21 févr. 2014 (il y a 4 années et 22 jours)

80 vue(s)


Lake Baikal



Deep water stratification and mixing



Alfred Wüest

31 October 2012, UniGE


Limnological Institute (RAS)


Physical Institute (ISU)


Earth Crust Institute (RAS)


Eawag (Swiss Fed)

Lake Baikal research



a collaborative effort

Lake Baikal South Basin



to shore 1.05 km

Depth 550 m

to shore 3.6 km

Moorings in South Basin

Depth 1363 m

N
et sedimentation

sed
-
water exchange

G
ross

sedimentation

3
.
0
0
3
.
1
0
3
.
2
0
3
.
3
0
3
.
4
0
3
.
5
0
T
e
m
p

°
C
L
a
k
e

B
a
i
k
a
l

N
e
u
t
r
i
n
o

s
i
t
e
T
R
1
0
0

8
8
2
0

1
3
6
3
m
1
1
-
M
a
r
-
0
3
2
5
-
M
a
r
-
0
3
8
-
A
p
r
-
0
3
2
2
-
A
p
r
-
0
3
6
-
M
a
y
-
0
3
2
0
-
M
a
y
-
0
3
3
-
J
u
n
-
0
3
1
7
-
J
u
n
-
0
3
1
-
J
u
l
-
0
3
1
5
-
J
u
l
-
0
3
2
9
-
J
u
l
-
0
3
1
2
-
A
u
g
-
0
3
2
6
-
A
u
g
-
0
3
9
-
S
e
p
-
0
3
2
3
-
S
e
p
-
0
3
7
-
O
c
t
-
0
3
2
1
-
O
c
t
-
0
3
4
-
N
o
v
-
0
3
1
8
-
N
o
v
-
0
3
2
-
D
e
c
-
0
3
1
6
-
D
e
c
-
0
3
3
0
-
D
e
c
-
0
3
1
3
-
J
a
n
-
0
4
2
7
-
J
a
n
-
0
4
1
0
-
F
e
b
-
0
4
2
4
-
F
e
b
-
0
4
9
-
M
a
r
-
0
4
2
3
-
M
a
r
-
0
4
T
i
m
e
Temperature at Neutrino site

Temperature

Temperature

at 1363 m depth

Cooling event

Mid Dec 2003

D
T =
-
0.18
o
C

3
/
8
/
0
2
3
/
2
2
/
0
2
4
/
5
/
0
2
4
/
1
9
/
0
2
5
/
3
/
0
2
5
/
1
7
/
0
2
5
/
3
1
/
0
2
6
/
1
4
/
0
2
6
/
2
8
/
0
2
7
/
1
2
/
0
2
7
/
2
6
/
0
2
8
/
9
/
0
2
8
/
2
3
/
0
2
9
/
6
/
0
2
9
/
2
0
/
0
2
1
0
/
4
/
0
2
1
0
/
1
8
/
0
2
1
1
/
1
/
0
2
1
1
/
1
5
/
0
2
1
1
/
2
9
/
0
2
1
2
/
1
3
/
0
2
1
2
/
2
7
/
0
2
1
/
1
0
/
0
3
1
/
2
4
/
0
3
2
/
7
/
0
3
2
/
2
1
/
0
3
3
/
7
/
0
3
3
/
2
1
/
0
3
T
i
m
e
3
.
0
0
3
.
1
0
3
.
2
0
3
.
3
0
3
.
4
0
3
.
5
0
T
e
m
p

°
C
T
R

1
0
0
0

8
8
2
7

1
3
6
3
m
m
Temperature

at 1363 m depth

Cooling event

Early Dec 2002

Temperature at Neutrino site

D
T =
-
0.35
o
C

1400
1200
1000
800
600
400
200
0
3.0
3.5
4.0
Temperature [

C]
Depth [m]
temperature of
maximum density
typical temperature profile
in June and December
Deep
-
water renewal!

how to push water below 300 m depth?

How to maintain
deep
-
water
temperature cold?

-
400 m

-
1460 m

Turbulent mixing

K
400m

= 12.5 m
2

s
-
1

Deep water intrusions

50 to 100 km
3

yr
-
1

z

Upwelling

w
400m

= 9 m yr
-
1

Long
-
term deep
-
water balance

How much methane is released?

Babushkin shallow

Yuri Parfenov

Elena Vologina

Nikolai Budnev

(1)

The deep
-
water below 300 m is permanently

stratified

(2)

The renewal of the water is by deep intrusions

after strong winds: 1% replaced per year

(3)


The water constituents follow the balance of

water replacement


downward diffusion

(4)


This mechanism is robust to climate change


(5)


The methane release is very small despite


the hydrants and the gas plumes.

Conclusions

Thank you