Hydrogeothermal Conditions in Ãire - Geological Survey of Ireland

More documents

Recommendations

Info

- 11 -It might be possible to go back over old records and the limitedpublications, to see if there have been significant changes in temperatureover tQe past 200 years or so. But the only old reliable data appears tolie is that given by Rutty for the period about 1757. He notes Mallow spawater as issuing at 68 0 F (20 0 C), as compared with 20.7 0 e measured on 15 Nov.1979 (Table 36. Rutty also notes that st. Margarets (NO. 1009)registered 51 F (lO.SoC) or 5S o F C12.8 0 C) on 20 July, 1752; this wouldcompare with 17.2 0 C on the morning of 7 December 1979. In a study of thebiology of the Enfield spring, Fahy (1975) gave some temperature figures,based apparently on a recording thermometer placed in the spring; hereports in his Table I a range from 6 0 to 22.5 0 C. He also states that thespring has a day-degree quota of 6,606, as against 3,835 for an Irishisothermic spring. Fahy (1975, p. 112) mentions but three thermal springsrecorded in Ireland, and introduces the supposedly warm spring at Dunlavinin Co. Wicklow, with the footnote "The area was visited by me; the springwas not located".From the periodic temperature measurements made on the mainLeinster group of springs (Fig. 2), those for the Enfield (NO. 1005) andst. Gormans (No. 1007) have been selected for presentation here, Fig. 3.During the eight years to end-1978, Enfield water temperature was recorded62 times and that of St. Gormans 64 times. No self-registering or min-maxthermometers were used. Periods when the springs had dried-up or becomestagnant were noted; such low/nil flows tended to occur from August toNovember. Figure 3 shows water temperature for Enfield and for st.Gormans over the calander years 1976 and 1978. These were years for whichgood records were available, and which come after the 1974-76 drought.The plottings show how temperatures reach a peak in the spring,and then fall quite sharply from May'to October, to rise again during thewinter. The discharges also increase in spring and fall in autumn. So,as flow increases, so does temperature; as flow decreases, so do temperaturesfall. It is considered that this relationship is of considerablesignificance. The source of the heat which warms the water must be muchgreater than the amount of heat taken away by the water. It suggests thatthe larger the volume of water moving underground, the more it is broughtinto contact with zones of more heat or higher temperatures. This mayindicate a deeper circulation in the ground when winter infiltration hasrecharged the aquifers and the water is moving strongly towards itsdischarge point.The degree-days for the two springs have also been calculated,due to irregularity of measurement and that fact that st. Gormans was dryfor part of the year, degree-days are only approximate. Enfield showed7820 degree-days (21.3S o C average) in 1976 and 7380 degree-days (20.22 0 Caverage) in 1978. St. Gormans showed_6230 degree-days in 1976 (17.06 0 eaverage) and 6790 degree-days (18.61 0 C average) in 1978. The differencesin average and from year to year may have significance, but certainlyneed to be related to volumes of water discharged if the data is to beused as an analytical tool./ ...
- 12 -iSpring No. 2001 2001 2002 2003 2003 1009 1001 1002 1003 1005 1005 1007 1008 1006 1004Sample NO. I II III IV V VI VII VIII IX X XI XII XIII XIV XVDate, 1979 15/11 15/11 15/11 4/12 4/12 7/12 7/12 7/12 7/12 7/12 7/12 7/12 7/12 7/12 7/12°c 11.3° 20.7° 17.6° 13.7° 13 .8° 17.2° 16.2° 13 .2° 14.2° 23.3° 23.3° 20.2° 13.0° 13.8° 12.2(Ca mgE/lit 4.72 3.60 4.20 3.44 3.40 6.84 5.92 4.60 5.60 3.92 3.84 4.80 6.56 5.76 4.64Mg 2.64 1.28 1.04 1.44 1.32 0.88 2.72 2.04 0.76 2.16 2.08 1.20 0.64 1.40 2.40Ma 0.31 0.50 0.47 0.60 0.59 0.56 9.09 0.43 0.39 1.13 1.13 0.41 0.31 0.48 2.61K 0.10 0.03 0.05 0.03 0.03 0.06 0.23 0.03 0.03 0.05 0.05 0.03 0.03 0.07 0.08Sum Cations 7.77 5.41 5.76 5.51 5.34 8.34 17.96 7.10 6.78 7.26 7.10 6.44 7.54 7.71 9.73HC03 mgE/lit 4.96 4.16 4.56 4.72 4.64 5.88 5.40 6.44 6.24 5.84 5.92 5.76 6.64 6.48 5.60Cl " 0.68 0.62 0.62 0.59 0.59 1.10 12.57 0.48 0.48 1.27 1.33 0.49 0.61 1.25 4.00N03 " 0.21 0.17 0.31 0.36 0.24 0.26 0.10 0.24 0.24 0.19 0.20 0.06 0.04 0.04 0.03S04 " 1. 92 0.46 0.27 - - l.10 - - - - - 0.15 0.25 - 0.12Sum Anions 7.77 5.41 5.76 5.67 5.47 8.34 18.07 7.16 6.96 7.30 7.45 6.46 7.54 7.77 9.75Ca mg/lit 236 180 210 172 170 342 296 230 280 196 192 240 328 288 232Mg " 132 64 52 72 66 44 136 102 38 108 104 60 32 70 120Na " 7 12 11 14 14 13 209 10 9 26 26 9 7 11 60K " 4 1 2 1 1 3 9 1 1 2 2 1 1 3 3HC0 mg/lit 3302 214 278 282 282 359 329 393 381 316 341 354 405 395 342Cl " 24 22 22 21 21 39 446 17 17 45 47 18 22 45 14211N0313 10 19 22 15 16 6 15 15 12 12 4 2 2 211S0492 22 13 - - 53 - - - - - 7 12 - -Sum of above 810 565 607 589 569 869 431 768 741 745 744 690 809 814 907Nitrate (as N) 3.0 2.4 4.4 5.0 3.4 3.6 1.4 3.4 3.4 2.6 2.8 0.8 0.6 0.6 0.45Free/Sol.Am. (N) 0.02 0.02 0.02 0.02 0.01 0.01 0.23 0.02 0.03 0.04 0.01 0.01 0.03 0.01 0.15Albuminoid (N) 0.29 0.02 0.02 0.02 0.01 0.02 0.01 0.07 0.06 0.01 0.01 0.01 0.02 0.01 0.01TDS (ppm) 370 286 334 296 292 528 1160 370 380 386 404 412 440 480 636Total Alkali 248 2208 228 236 232 296 296 322 312 292 296 288 332 324 280Total Hardness 368 244 262 244 236 386 432 332 318 304 296 300 360 358 352pH 7.40 7.52 7.41 7.60 7.84 7.23 7.28 7.24 7.26 7.31 7.35 7.26 7.11 7.19 7.32TABLE 3. Temperatures and main chemical constituents of the waters of the Irish warm springs, based on samples takenon 15 November and 4 and 7 December, 1979. Analyses made at State Laboratory, College of Science, Dublin.
Page 1 and 2: IIII1HXDROGEOTHERMAL CONDXTXONSIN E
Page 3 and 4: convection uprising of warm water i
Page 5 and 6: BallinalackNo .1011Hurler's .Cro~5N
Page 7 and 8: - 2 -Normal groundwater in Ireland
Page 9 and 10: - 3 -Ref. No.Name or NamesCounty100
Page 11 and 12: - 5 -II-l. LocationThe general loca
Page 13 and 14: - 7 -Thickness(m)Lithology+ 335 m+
Page 15 and 16: - 9 -Boreholes drilled for water, p
Page 17: IIII.JJJ.S 0 .No-- --~--f-22C:1. -
Page 21 and 22: - FIGURE 5 - TRACE ELEMENTS SILICON
Page 23 and 24: - 14 -Spring No. 2001 2001 2002 200
Page 25 and 26: M'ddl~Slo9~CrySlol\'n~ bos.m.ntor d
Page 27 and 28: FIGURE 7 - POSSIBLE PRESENT~DAY GRO
Page 29 and 30: - 18 -The effects of the varying th
Page 31 and 32: - 20 -CLAYTON, G. and HIGGS, K. (19

Hydrogeothermal Conditions in Ãire - Geological Survey of Ireland

Create successful ePaper yourself

Delete template?

Save as template?

Hydrogeothermal Conditions in Ãire - Geological Survey of Ireland