Records of Milne Seismograph No. 20, At Wellington, From October, 1900, To December, 1901 (Inclusive)

Transactions and Proceedings of the Royal Society of New Zealand, Volume 34, 1901, Page 598

Records of Milne Seismograph No. 20, At Wellington, From October, 1900, To December, 1901 (Inclusive) Plates XLI. And XLII. Latitude, 41° 17′ S.; longitude, 174° 47′ E. Time employed, 11 b. 30 m. east of Greenwich (New Zealand mean time). Midnight, 0 h. or 24 h.; hours, 1 to 24. Record number 1, 2, … from the 1st October, 1900. P.T., preliminary tremors. A.T., after-tremors. B., E., beginning and end of vibrations generally not less than 2 mm. Amp., full amplitude in millimetres. The period of the boom of the pendulum during the currency of these records was kept as near to 16½ seconds as possible. The instrument is placed in a special room below a house standing about 30 ft. from the edge of a rocky cliff about 50 ft high, situated about 250 yards from the shore-line of Wellington Harbour. George Hogben, Observer. No. Date. P.T. (from) B Maxima Amp. E A.T. (till) Remarks From To 1900. Mm. 1 Oct. 3 13.17 ? 17 41 2 Two maxima. 20.40 6 ? 22 45+ 2 " 4 1.57 ? 2.52½ 1.5 38½ ? 8 16 " 3 " 4 8.51 9.51 9 52½ 11 9 2 11.9 12 5 " 4 " 4 17.8 17.8 small 8.5+ 5 " 5–6 23.57 2.48 2 56 3.4 4.50 Tremors; 5, 6, and 7 are continuous. 6 " 6 4 56 6.33½ 6.35 13 6.38 9 53+ 7 " 6 9 53 13.17 Two maxima. 14.1 2 15.4 8 " 8 2.4 2.25 2.52 2.5 3 8 3.23 6.40 " 9 " 8 6.42 8 54½ 9 1 9 9 22 9.28 10 20

10 Oct. 8 12.17 13.50+ Minute tremors. 11 " 8 20.7 20.37 7 20.49 21.37 12 " 8 22.10 " 9 1.50 13 " 9 2.50 8.4 " 14 " 9 8.4 8.5½ 1.5 9.4 19.30+ 15 " 10 ? 0.36 0.56 11 Origin in Alaska. 2.17 8 2 43 ? 16 " 16 22.43 22.48½ ? 22.54½ Small local shock. 17 " 21 4.59 6.18 6.25 6 30 3.5 ? 6.56 6.28⅓ 18 " 22 12.7 16.31 Very small tremors. 19 " 23 10.32 15.25 " 20 Nov. 24 23.34 " 25 6.32 Nine small local shocks. 21 " 25 21.18½ Small local shock. 22 Dec. 16 11.37 12.29 9 13.25 Nine small shocks, one large. 23 " 17 8.4 8 14 2.5 8.35 Five small shocks. 24 " 17 11 53 12.14 5 12.53 Seven small shocks. 25 " 18 8.28 9 15 4.5 9.26 Six small shocks. 9.57½ 10 38 18.37 Large tremors. 26 " 19 9.55 10.6 10 10.56 21.54 Small tremors. 10.46½ 10.51 8 27 " 23–24 5.55* About. 18.57 18.57 8 19.1 3 41+ Minute tremors for some hours after. 28 " 24 10 25* 18.45* Small tremors. 29 " 25–26 18.30* 5.20* Tremors. 30 " 26–27 12.18 18.8 18.9 2.5 18.17 10.38 Many small shocks. 31 " 27 11.42 12.57 Tremors. 32 " 28 8.43 ? 9.53½ 2 14.38 Slight;? local. 33 " 30–31 15.0* 5.30* Tremors and slight shocks. " 31 11.24 Centre line changing position. 1901. 34 Jan. 1 0 28 Wave in centre line (see record for January, 1901.) No tremors or shocks. Record defective for most of month of November owing to absence of observer. Record incomplete during first part of December.

1900. Mm. 35 Jan. 1 Wave in centre line; period, 13 h. 4 m.; complete amplitude, 6.5 mm 36 " 2 19.34 22.33½ 22.46½ 3 22.53 23.25+ " 3 bef.19.36 37 " 4 0.3 0.5¼ 2.5 0.7 Continuous tremors from 19.36 on the 3rd January to 16.34 on the 6th January. " 5 38 " 6 9.6½ 9.13 2.5 9.19 16.34+ Lamp went out at 16.34 39 " 6 21.53 22.55½ 23.0 23.26 No. 39 is continuous with No. 40. " 7 1.2 23.0 Also smaller shocks at 1.7, 1.14, 1.43, 1.46½, 2.38, 2.46, 4.52, &c., with tremors between. 40 " 7 12.21½ 12.43¾ 12.51 7.5 12.59½ The tremors that had been going on for some days became more marked at 12.21½. 41 " 8 1.20 ? 3.49 1 Followed by other maxima at 9.53 and 10.9½. 4.19 1 42 Jan. 8 10.44 10.51 2 10.53 12.38 12.51 1.5 12.55 Followed by other maxima at 14.5, 14.14, 15.23, 15.44½, 16.3, 16.11, 17.0½. 43 " 8 ? 21.33 3.5 ? ?Local. Followed by other slighter shocks till 5.24, 9th January. 44 " 9 0.33 38 4.57½ 11 45 " 9 9.30 9.31 9.58½ 4 Probably local. 10.10 2.5 10.33 4 11.5 7 46 " 9 12.53 12.59 ? 13.0½ With other smaller maxima.

47 Jan. 14 4.49 ? 7.40½ 1 15.14 18.25 48 Jan.15 10 32 Minute tremors. " 16 17.48 49 " 18 8.29 ? Minute tremors till after 9.59, when lamp went out. 50 Feb. 4 10.30 18.30½ 5 Large tremors; no distinct earthquake. " 5 7.39 51 " 5 9.57 2.5 12.52 Tremors; no marked shocks. 52 " 5 21.41 Minute tremors. " 6 6.18 53 " 6 6.18 7.55½ 7.57½ 13.5 ? After-tremors of great length. " 7 15.11 54 " 8 7.42 18.34 Tremors. 55 " 10 7.13 7.13 7 7.14 Local. 56 " 10 8.32 8.33 4.5 8.33½ " 57 " 10 9.32 9.36 2 9.36 " 58 " 10 14.31 14.32 2.5 14.32 Local; tilt 2 mm, to west. 59 " 10 15.42 15.42 3 15.42 Local; tilt 1.5 mm. to east. 60 " 19 16.29½ 16.34 16 16.36½ Local. 61 " 10 19.5 19 5 6 19.5 Local; tilt 2 mm. to east. 62 " 10 19.28 19.33 3 19.34½ Local. 63 " 10 ? 22.48½ 22.53 3.5 ? Local; tilt 0.5 mm. east. 64 " 10 23.29 23.36½ 5 23 39 65 " 11–14 A few minute tremors. 66 " 20 2.44 3.15 3.18 1 3.19 3.23 Local. 67 March 15 ? 23.17 ? ? Very small; local. 68 " 16 ? 21.37 4 ? Change of level; local. 69 " 19 ? 3.21 1 ? Local. 70 " 23 ? 16 35 ? ? Very small; local. 71 April 30 4.42 4.42 5 4.42½ Local 72 " 30 4.59 4.59 5.0 4 5.0½ Local; two maxima. 73 " 30 5.17 5.17 29 5.17½ ? Local; tilt 4 mm. to west; after-tremors for nineteen hours. Record defective for first ten days of April; clock out of order. Again from 17th to 25th April; clock out of order.

1900. Mm. 74 May 3 10.52 21.20 Very small tremors. 75 " 4 5 20 9 39 9.40½ 4 9.43 Continuous tremors between; followed by minute tremors. 76 " 4 15.47 15.53 3 15.59 16.24 77 " 5 1.33 Large tremors from 12.45 to 13.50; rest small or minute tremors. " 6 0 6 78 " 6 4.15* 18.15* Very small tremors. 79 " 7 1.11 17.47 Small to very small tremors. 80 " 8 5.33 12.15 Very small tremors, followed by minute tremors till 15.25. 81 " 9 10.33 20.30 Very small tremors. 82 " 9 21.17 Tremors gradually increasing from minute to moderate (1 or 1.5 mm). " 10 8.30* 83 " 10 8.32 9.26 9.26½ 1.5 10–11 May: chief maxima, as named. " 10 10.45¾ 3.5 Also at 10.54¾ (2.5 mm.), 10.57½ (2.5 mm.). " 10 11.27¼ 3 75 Also at 12.13 (2 mm.), 13.3 (3 mm.), 14 36¼ (2 mm.). " 10 17.6¼ 3 5 " 10 17.47 17.50½ 3 Also at 19.17–19.26¼ (2.5 mm.) and 19.58 (2.5 mm.). " 10 20.15½ 20 47 5 Also at 22 6, 22.24, and 22.32 (all 3 mm.). " 10 22.52½ 22 54¼ 23.6¼ 4.75 Also at 0.10, 0.13, 0 18½ (all 2.5 mm.). " 11 0.42 0.48 0.51 3.75 0.57 3.29 84 " 11 3.54 11.53 Very small tremors. 85 " 11 19.24 19.27 1 19.28 ? Local. 86 " 12 1 48 1.48 2.6 3 2 6 Probably local. 87 " 13 2.38 2.51 2.51 2 2.51 ? Local.

88 May 17 16.36 15.36 ? 15.36 Very small local shocks. 89 " 17 22.30 22 30 ? 22.30 90 " 18 0.30 10.32 Tremors, minute, with a few moderate 91 " 19 5 15 15.12 Minute tremors. 92 " 22 5.28 19.24½ " 93 June 6 13 26 Local; level tilted 4 mm. to west. 94 " 6 18.11 20.42 Very small tremors. 95 " 6 20 52 Minute tremors. 96 " 10 17.49 17 51 5 17.53 Local. 97 " 11 2.32½ 2.34 4 2.37 " 98 " 27 ? 22.47 22 47 23.51 2–3 23 54 Fifteen shocks, or maxima; eighteen similar shocks of shorter duration, till about 2.45 on the 29th June. 99 " 29 13.48 13.51 14.2 6 14.6 Local. 100 " 29 14.29½ 14.30 14.32½ 14.37 " 101 " 29 15 53 16 2 16 27 ? Local. 102 " 29 17.31½ 17.31½ 7 17.49 " 103 " 29 18 43 18 51 5 18.56 " 104 " 29–30 23.35 23.45 23.57 4 0.1 " 105 " 30 0.54 0.54 1 7 16 " 106 " 30 3.41½ 3.42 4 3.49 " 107 " 30 10.49 10.55 6 11 5 " 108 " 30 12 54 12 56 13.5 3 13 8 " 109 " 30 13 40 13.40 13.41 4 13 45 " 110 " 30 18 1 18 6 5.5 18.9 " 111 " 30 21.26 21.26 21.47 4 21.52 " 112 " 30 23 3 23.3½ 10 23.28 " 113 July 1 1.30 22 45 Eleven shocks similar to those of 29th June, but shorter. 114 " 3 10 46 14 22 Small tremors. 115 " 4 6.37 17.38 " 116 " 19 21.19 23 34 Very small tremors. 117 " 21 6.9 14.13 Tremors, minute for about seven hours, then small. It is possible, but not likely, that some of the shocks from the 27th to the 30th June may be instrumental.

1901. Mm. 118 July 25 9.37 19.45* Minute tremors. 119 " 26 6.30* 8.25* " 120 " 29 22.6 Tremors. " 30 6.24 121 " 30 10.39 14.43 " 122 " 30 15.39 22.0 22.4 22.6 3.5 ? " 31 13.25 123 Aug. 2 2.14 9.47 Small tremors. 124 Aug. 2 15.36 " Aug. 3 19.24 125 Aug. 4 3.20 Very small tremors, with intervals of rest. Aug. 5 0.55 126 Aug. 6 19.48 19 55 Tremors. 127 Aug. 9 21.8 21.35 22.4 6 22.12 23.6 128 Aug. 10 0.38 0.51 1.25† Other maxima or large tremors up to 10 mm. in amplitude for more than one hour later >40 2.46 ? 129 Aug. 10 ? 3.36 3.44 4.10 5 4.17 5.4 130 Aug. 10 6.0 6.44 7.11 7.23 4 7.26 9.20+ 131 Aug. 10 21.59 22.18 22 23 22.33 6 22.38 23.43 132 Aug. 11 3.33 3.34 3.35½ 3.39 2 3.42 Probably local. 133 Aug. 11 6.22 6.35 Tremors. 134 Aug. 11 9.12 9.26 " 135 Aug. 11 17.34 22.28 Minute tremors. 136 Aug. 12 1.36 2.7 2.12 2.24 11 2.40 4.4 137 Aug. 13 7.37 7.52½ Small tremors. 138 Aug. 13 21.5 Tremors, large and small. Aug. 14 14.48 139 Aug. 14 18.10 18.41 Small tremors. 140 Aug. 14 20.37 Tremors, moderate to minute. Aug. 15 23.8

141 Aug. 16 8.40 9.34 Minute tremors. 142 " 16 20.37 21.11 Tremors. 143 " 17 7.45 Minute tremors, dying away slowly. " 18 6.41 144 " 19 7.38 Minute for 25½ hours, then moderate to large. " 20 20.16 145 " 20 21.6 Tremors. " 21 6.2 146 " 21 18 43 " " 23 21.49 " 147 " 25 9.11 9.11 3 9.11½ ? Local. 148 " 25 9.35 9.36 11 9.36½ Two maxima. 149 " 25 10.41 10.41 26 10 43 " 28 4.37 150 " 29 ? 9.24 2–3 17 0 Long series of vibrations. " 30 1.28 151 Sept. 4 8.15 Minute tremors, with intervals of rest. " 5 19.1 152 " 6 84 19.4 " " 153 " 7 19.7 21.37 " " 154 " 8 10.30 10 38 10.41 10.45 4 11.0½ 11.18 155 " 9 5 19 5.31 5.32 5.33½ 16 5 36 After-tremors, many large, with intervals of rest. " 10 19.20 156 " 10 20.44 Tremors, minute at first. " 11 5.2 157 " 11 8.43 9.14 Very small tremors. 158 Oct. 19 9.21 9.21 9.33 1.5 9.34 Three maxima.? Local. 159 Nov. 16 7.47 7.47½ 7.49¼ >40 7.58¼ 8.58 Local. Earthquake in Cheviot district, Canterbury and Nelson. Large tremors till 8.58, followed by continuous small tremors (with very few intervals) and many small shocks until 17 h. on the 19th November, with intensity IX. on Rossi-Forel scale. " 19 17.0 160 " 20 10 30* 19.0* Very small or minute. The clock was out of order and was away for repairs during part of October. * About.

1901. Mm. 161 Nov. 21 6.20* ? 11.18½ 1 ? Tremors; local. " 22 0.20 162 " 23 2.45* Minute to small tremors. " 25 *13 30 163 " 25 13.32 13.50 13 53 13.56 8 14.2 14 56 Probably non-local. 164 " 25 19.25 Tremors; probably local. " 26 13.20 165 " 27 7.35 18 20 " " 166 " 28 2 37 ? 7.44½ † Other maxima till 11 4. Tremors marked but small, dying away to minute.8.29¾ 2.5 17.3 167 " 29 3.50 11 40 Moderate. " 30 18 18 Minute. 168 " 31 20.4 Very small tremors. Dec. 1 8.47 169 " 1 8.52½ 2 8 58½ Tremors between. 170 " 1 ? 9.46 9 48½ 8 9 51 171 " 22 1 34 1.34 1 1 38 Local. 172 " 23 6.15¾ 6 16¾ 2.5 6 19¼ " 173 " 23 8 26½ 8 26½ 2 5 8 29½ " 174 " 24 7.7¼ 7.7¼ 1 7.9 ? Local. 175 " 25 11.21 11.47¾ 3 11 51½ " 176 " 25 14.45 14 45 3.5 14.47½ Local. 177 " 26 14 9 14 41 14.44 Minute tremors. 178 " 26 21 38 21.40½ 21.44¼ 21.49¼ 6 5 22 7 23.14¾ 179 " 27 10.4 12.10 " 180 " 27 21 53½ 21 53½ 4 21 57 Local. 181 " 28 50 14 6¾ 2 20 7¼ Tremors, mostly minute or very small. 182 " 31 20 56 21 21¼ 21 25¾ 2 21 28½ 21.38 Many minute tremors and small shocks separated by longer intervals from 1st to 22nd December; probably all local (Cheviot).