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Table 7 Estimated increase in NH4+ concentration of the Hadean Ocean (in μmol.L-1) from the hydrothermal N2 reduction reaction per 1 Ma as a function of N2-to-NH4+ conversion percentages, heat flow and percentage of heat released via hydrothermal systems.

From: Abiotic ammonium formation in the presence of Ni-Fe metals and alloys and its implications for the Hadean nitrogen cycle

5% of Earth's heat flow is released via hydrothermal activity

N 2 conversion

Hadean heat flow (× PDHF)

%

4

5

6

7

8

0.1

0.4

0.5

0.6

0.8

0.9

0.5

2.1

2.7

3.2

3.8

4.3

1

4.3

5.4

6.4

7.5

8.6

2

8.6

10.7

12.9

15.0

17.2

5

21.4

26.8

32.2

37.5

42.9

10

42.9

53.6

64.3

75.0

85.8

20% of Earth's heat flow is released via hydrothermal activity

N 2 conversion

Hadean heat flow (× PDHF)

%

4

5

6

7

8

0.1

1.7

2.1

2.6

3.0

3.4

0.5

8.6

10.7

12.9

15.0

17.2

1

17.2

21.4

25.7

30.0

34.3

2

34.3

42.9

51.5

60.0

68.6

5

85.8

107

129

150

172

10

172

214

257

300

343

80% of Earth's heat flow is released via hydrothermal activity

N 2 conversion

Hadean heat flow (× PDHF)

%

4

5

6

7

8

0.1

6.9

8.6

10.3

12.0

13.7

0.5

34.3

42.9

51.5

60.0

68.6

1

68.6

85.8

103

120

137

2

137

172

206

240

274

5

343

429

515

600

686

10

686

858

1030

1200

1370