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Table 2 Variation in the mean annual frequency of tephra fall (λan) events exceeding 0 mm and equal to or greater than 10, 100, 200, and 500 mm for every 10 kyr period extended from present to 150 kyr at Tokyo. t: tephra fall deposit thickness (mm); Conf_95_max and Conf_95_min: maximum and minimum values of the 95% confidence interval, respectively. ND: not defined

From: Creating a digital database of tephra fallout distribution and frequency in Japan

Age (ka)

t > 0 (× 10− 4)

t ≥ 10 (× 10− 4)

t ≥ 100 (× 10− 4)

t ≥ 200 (× 10− 4)

t ≥ 500 (× 10− 4)

0–10

5.00

3.00

0.00

0.00

0.00

0–20

4.00

2.00

0.50

0.00

0.00

0–30

3.00

1.67

0.67

0.00

0.00

0–40

2.25

1.25

0.50

0.00

0.00

0–50

1.80

1.00

0.40

0.00

0.00

0–60

1.50

0.83

0.33

0.00

0.00

0–70

1.43

0.86

0.43

0.00

0.00

0–80

1.25

0.75

0.38

0.00

0.00

0–90

1.33

0.89

0.44

0.11

0.00

0–100

1.30

0.90

0.40

0.10

0.00

0–110

1.27

0.91

0.36

0.09

0.00

0–120

1.25

0.92

0.33

0.08

0.00

0–130

1.31

1.00

0.38

0.08

0.00

0–140

1.21

0.93

0.36

0.07

0.00

0–150

1.13

0.87

0.33

0.07

0.00

Mean

1.94

1.18

0.39

0.04

0.00

Conf_95_max

2.58

1.52

0.47

0.07

ND

Conf_95_min

1.29

0.85

0.31

0.02

ND