Table 2.

Table 2. Results from PCS gas-release experiments.

Core High pressure
air volume
(mL) Threshold pressures
(MPa) Total gas volume
(mL) CH₄
volume
(mL) 0°C total gas volume
(mL) 0°C CH₄
volume
(mL) Average 0°C CH₄ release rate
(mL/min)

164-994C-

70P
120
1.9, 1.1
720 (+1)
600 (+1)
720 (+2)
600 (+2)
32

164-995A-

0P*
140
<0.4
140 (+1)
0 (+1)
140 (+2)
0 (+2)
0

18P
60
NA
555 (++3)
495 (++3)
555 (++3)
495 (++3)
7

27P
105
3.9, 1.5
4215
4110
3975 (++2)
3870 (++2)
17

36P
130
2.1, 1.4
1430 (+3)
1300 (+3)
1420 (+2)
1290 (+2)
9

45P
175
4.4, 1.1
4310
4135
4140 (+2)
3965 (+2)
60

48P
125
3.8, 1.5
860 (+4)
735 (+4)
690 (+2,+4)
565 (+2,+4)
8

52P*
85
NA
85
0
No ice
No ice
NA

52P
65
2.0
2365
2300
2225 (+2)
2160 (+2)
70

60P
70
>0.2
1310
1240
1035 (++2)
965 (++2)
22

70P
75
>0.1
285
210
No ice
No ice
NA

164-995B-

7P
80
1.9
2330 (+1)
2250 (+1)
2330 (+2)
2250 (+2)
15

10P
125
3.0, 0.9
980
855
680 (++2)
555 (++2)
4

164-996A-

7P
100
3.2
5415
5315
5030 (++2)
4930 (++2)
7

164-996D-

7P
130
2.9
8100
7970
7810 (++2)
7680 (++2)
8

164-996E-

8P
125
NA
575
450
No ice
No ice
NA

164-997A-

18P
175
2.9, 0.3
450
275?
270
95
1

25P
90
NA
7485
7395
Unknown (5)
Unknown (5)
High (5)

33P
115
1.2, 0.2
290
175
255
130
2

49P
130
3.3
7050
6920
6785 (+2)
6655 (+1)
42

55P
145
3.0
6380
6235
5600 (++3)
5455 (++3)
43

164-997B-

10P
130
3.8 (6)
5125
4995
5035
4905
22

15P
40
1.2
3190
3150
3080
3040
10

21P
170
1.8
3455
3285
3115 (++2)
2945 (++2)
35

29P*
110
0.1
110
0
110
0
0

32P
70 (+1)
0.1
70 (+1)
0 (+1)
70 (+2)
0 (+2)
0

36P
120
0.3
120
0
110 (+2)
0 (+2)
0

40P
70
0.2
70
0
70
0
0

44P
80
0.2
80
0
80
0
0

Core	High pressure air volume (mL)	Threshold pressures (MPa)	Total gas volume (mL)	CH₄ volume (mL)	0°C total gas volume (mL)	0°C CH₄ volume (mL)	Average 0°C CH₄ release rate (mL/min)
164-994C-
70P	120	1.9, 1.1	720 (+1)	600 (+1)	720 (+2)	600 (+2)	32
164-995A-
0P*	140	<0.4	140 (+1)	0 (+1)	140 (+2)	0 (+2)	0
18P	60	NA	555 (++3)	495 (++3)	555 (++3)	495 (++3)	7
27P	105	3.9, 1.5	4215	4110	3975 (++2)	3870 (++2)	17
36P	130	2.1, 1.4	1430 (+3)	1300 (+3)	1420 (+2)	1290 (+2)	9
45P	175	4.4, 1.1	4310	4135	4140 (+2)	3965 (+2)	60
48P	125	3.8, 1.5	860 (+4)	735 (+4)	690 (+2,+4)	565 (+2,+4)	8
52P*	85	NA	85	0	No ice	No ice	NA
52P	65	2.0	2365	2300	2225 (+2)	2160 (+2)	70
60P	70	>0.2	1310	1240	1035 (++2)	965 (++2)	22
70P	75	>0.1	285	210	No ice	No ice	NA
164-995B-
7P	80	1.9	2330 (+1)	2250 (+1)	2330 (+2)	2250 (+2)	15
10P	125	3.0, 0.9	980	855	680 (++2)	555 (++2)	4
164-996A-
7P	100	3.2	5415	5315	5030 (++2)	4930 (++2)	7
164-996D-
7P	130	2.9	8100	7970	7810 (++2)	7680 (++2)	8
164-996E-
8P	125	NA	575	450	No ice	No ice	NA
164-997A-
18P	175	2.9, 0.3	450	275?	270	95	1
25P	90	NA	7485	7395	Unknown (5)	Unknown (5)	High (5)
33P	115	1.2, 0.2	290	175	255	130	2
49P	130	3.3	7050	6920	6785 (+2)	6655 (+1)	42
55P	145	3.0	6380	6235	5600 (++3)	5455 (++3)	43
164-997B-
10P	130	3.8 (6)	5125	4995	5035	4905	22
15P	40	1.2	3190	3150	3080	3040	10
21P	170	1.8	3455	3285	3115 (++2)	2945 (++2)	35
29P*	110	0.1	110	0	110	0	0
32P	70 (+1)	0.1	70 (+1)	0 (+1)	70 (+2)	0 (+2)	0
36P	120	0.3	120	0	110 (+2)	0 (+2)	0
40P	70	0.2	70	0	70	0	0
44P	80	0.2	80	0	80	0	0

Notes: Threshold pressures are not accurate because release of small volumes of gas could not be controlled at high pressure. (+) = potential small addition; (++) = potential large addition; * = runs where the PCS was configured to collect a water sample only, no core was taken. NA = not applicable. (1) = PCS not warmed; minimum total gas volume; (2) = PCS not maintained at 0°C, 0.1 MPa for a long time; minimum volumes; (3) = port clog; (4) = a small but unknown quantity of gas was lost from Core 164-995A-48P; (5) = gas released from this core rapidly under warming conditions; (6) = temperature greater than 0°C when core was first opened.