106:
440:(IAEA) recommended the preparation of two water isotopic standards: Vienna SMOW (VSMOW; initially just "SMOW" but later disambiguated) and Standard Light Antarctic Precipitation (SLAP). Craig prepared VSMOW by mixing distilled Pacific Ocean water with small amounts of other waters. VSMOW was intended to match the SMOW standard as closely as possible. Craig's measurements found an identical O concentration and a 0.2‰ lower H concentration. The SLAP standard was created from a melted
298:
836:, which makes its definition completely independent of the properties of water. The defined value for the Boltzmann constant was selected so that the measured value of the VSMOW triple point is identical to the prior defined value, within measurable accuracy. Triple-point cells remain a practical method of calibrating thermometers.
816:
temperature scale would refer to water with a composition of the nominal specification of VSMOW. The decision was welcomed in 2007 by
Resolution 10 of the 23rd CGPM. The triple point is measured in triple-point cells, where the water is held at its triple point and allowed to reach equilibrium with
486:
in Israel, and a well in Egypt, in proportions chosen to reach VSMOW isotopic ratios. The IAEA also published a successor to SLAP, called SLAP2, derived from melted water from four
Antarctic drilling sites. Deviations of O, and O in the new standards from the old standards are zero within the error
73:
to contain slightly different ratios of isotopes. Ocean water (richer in heavy isotopes) and rain water (poorer in heavy isotopes) roughly represent the two extremes found on Earth. With VSMOW, the IAEA simultaneously published an analogous standard for rain water, Standard Light
Antarctic
698:
The concentrations of O, and O are indistinguishable between VSMOW and VSMOW2, and between SLAP and SLAP2. The specification sheet gives the standard errors in these measurements. The concentration of H is unchanged in VSMOW2 as well, but is slightly increased in SLAP2. The IAEA reports:
131:
477:
In
December 1996, because of a dwindling supply of VSMOW, the IAEA decided to create a replacement standard, VSMOW2. Published in 1999, it contains a nearly identical isotopic mixture. About 300 liters was prepared from a mixture of distilled waters, from
473:
of SLAP is −428‰, relative to VSMOW. Therefore, SLAP is defined to contain 94.45% the oxygen-18 concentration and 57.2% the deuterium concentration of VSMOW. Using a scale with two defined samples improves comparison of results between laboratories.
619:
for O and −428‰ for H. That is, SLAP was measured to contain approximately 5.55% less oxygen-18 and 42.8% less deuterium than does VSMOW, and these figures were used to anchor the scale at two points. Experimental figures are given below.
782:
Variations in isotopic content are useful in hydrology, meteorology, and oceanography. Different parts of the ocean do have slightly different isotopic concentrations: δ O values range from –11.35‰ in water off the coast of
460:
The deuterium and oxygen-18 concentrations in VSMOW are close to the upper end of naturally occurring materials, and the concentrations in SLAP are close to the lower end. Due to confusion over multiple water standards, the
448:
in
Antarctica. A standard with oxygen-18 and deuterium concentrations between that of VSMOW and SLAP, called Greenland Ice Sheet Precipitation (GISP), was also prepared. The IAEA began distributing samples in 1968, and
293:{\displaystyle \delta \,^{2}\mathrm {H} _{x/{\text{reference}}}{\text{ (in ‰)}}=\left({\frac {(^{2}\mathrm {H} /^{1}\mathrm {H} )_{x}}{(^{2}\mathrm {H} /^{1}\mathrm {H} )_{\text{reference}}}}-1\right)\cdot 1000}
787:
to +1.32‰ in the north
Atlantic, and δ H concentrations in deep ocean water range from roughly –1.7‰ near Antarctica to +2.2‰ in the Arctic. Variations are much larger in surface water than in deep water.
361:
69:(H), has a melting point of 3.82 °C (38.88 °F) and boiling point of 101.4 °C (214.5 °F). Different rates of evaporation cause water samples from different places in the
453:
compiled analyses of VSMOW and SLAP from 45 laboratories around the world. The VSMOW sample was stored in a stainless-steel container under nitrogen and was transferred to glass
771:
The VSMOW–SLAP scale is recommended by the USGS, IUPAC, and IAEA for measurement of deuterium and O concentrations in any substance. For O, a scale based on Vienna
1120:
509:. Measurements of particular combinations of oxygen and hydrogen isotopes are unnecessary because water molecules constantly exchange atoms with each other.
1157:
462:
1131:
494:
is defined to be −427.5‰ instead of −428‰—but not in VSMOW2 from VSMOW. The IAEA recommends that measurements still be reported on the VSMOW–SLAP scale.
465:
recommended in 1994 that all future isotopic measurements of oxygen-18 (O) and deuterium (H) be reported relative to VSMOW, on a scale such that the
1684:
The
International Committee for Weights and Measures (CIPM) decides the definition of the kelvin refer to water of a specified isotopic composition
809:
797:
27:
1217:
776:
1209:
117:
Abundances of a particular isotope in a substance are usually given relative to some reference material, as a delta in parts per thousand (
42:
are accurately known. VSMOW is distilled from ocean water and does not contain salt or other impurities. Published and distributed by the
57:
Water samples made up of different isotopes of hydrogen and oxygen have slightly different physical properties. As an extreme example,
1184:
Lin, Y.; Clayton, R. N. (2010). "Calibration of δO and δO of international measurement standards – VSMOW, VSMOW2, SLAP, and SLAP2".
1102:
1801:
1087:
845:
1658:
1696:
517:
Except for tritium, which was determined by the helium gas emitted by radioactive decay, these measurements were taken using
307:
889:
375:
1094:
437:
418:
47:
817:
its surroundings. Using ordinary waters, the range of inter-laboratory measurements of the triple point can be about
382:, California, proposed an abstract water standard. He based the proportions on his measurements of samples taken by
1224:
1848:
997:
1853:
81:
A scale based on VSMOW and SLAP is used to report oxygen-18 and deuterium concentrations. From 2005 until its
421:
defined another abstract reference, also called "SMOW", for oxygen-18 concentrations, such that a sample of
391:
1843:
1040:
919:
1814:
1769:
1088:"Advisory Meeting on Stable Isotope Reference Samples for Geochemical and Hydrological Investigations"
808:
of water. Waters with different isotopic compositions had slightly different triple points. Thus, the
972:(9 June 1961). "Standard for Reporting Concentrations of Deuterium and Oxygen-18 in Natural Waters".
995:
Epstein, S.; Mayeda, T. (1 November 1953). "Variation of O content of waters from natural sources".
1725:
1018:
Gonfiantini, R. (February 1978). "Standards for stable isotope measurements in natural compounds".
1205:
1774:
829:
370:
In 1961, pursuing a standard for measuring and reporting deuterium and oxygen-18 concentrations,
82:
487:
of measurement. There is a small but measurable deviation of H concentration in SLAP2 from SLAP—
50:
in 1968, the standard and its essentially identical successor, VSMOW2, continue to be used as a
1142:
1060:"Absolute isotopic scale for deuterium analysis of natural waters. Absolute D/H ratio for SMOW"
911:
390:
his "standard mean ocean water" (SMOW) relative to a water sample held in the United States'
1165:
121:) from the reference. For example, the ratio of deuterium (H) to hydrogen-1 in a substance
8:
1109:
912:"Reporting of stable hydrogen, carbon, and oxygen isotopic abundances (Technical Report)"
850:
386:
of ocean waters around the world. Approximating an average of their measurements, Craig
1858:
1656:
833:
51:
821:. With VSMOW, the inter-laboratory range of measurements of the triple point is about
74:
Precipitation (SLAP), and eventually its successor SLAP2. SLAP contains about 5% less
1768:
Pitre, Laurent; Plimmer, Mark; Sparasci, Fernando; Himbert, Marc (20 December 2018).
1669:
1010:
974:
902:
518:
422:
105:
1193:
1073:
1049:
1027:
1006:
983:
955:
946:
928:
898:
775:
can also be used. The physical samples, which are distributed by the IAEA and U.S.
772:
1703:
1659:"Clarification of the definition of the kelvin, unit of thermodynamic temperature"
987:
1818:
1258:
1233:
445:
1078:
1059:
887:
Baertschi, P. (August 1976). "Absolute O content of standard mean ocean water".
30:
for water, that is, a particular sample of water whose proportions of different
506:
483:
479:
1837:
1806:
1711:
The CIPM's adoption of the VSMOW standard was based upon a recommendation in
395:
932:
969:
805:
371:
94:
1218:"Report of Stable Isotopic Composition Reference Material SLAP2 – 0.25 μL"
1740:
Supplementary
Information for the International Temperature Scale of 1990
1179:(6). Commission on Isotopic Abundances and Atomic Weights: 683–800. 2000.
70:
58:
1828:
1823:
398:). In particular, SMOW had the following parameters relative to NBS-1:
66:
1657:
International
Committee for Weights and Measures (CIPM) (2005-10-10).
1742:. International Committee for Weights and Measures. 1997. p. 29.
1197:
1031:
960:
941:
784:
616:
591:
573:
525:
497:
The older two standards are now kept at the IAEA and no longer sold.
379:
118:
75:
62:
436:
To resolve the confusion, November 1966 meeting of the Vienna-based
1108:. International Atomic Energy Agency. December 2006. Archived from
1064:
35:
1638:
539:
454:
31:
1508:
1506:
1697:"94th Meeting of the Comité International des Poids et Mesures"
813:
801:
86:
43:
39:
1041:"Measurement of the absolute abundance of oxygen-17 in V-SMOW"
1503:
1039:
Li, Wenjun; Ni, Baoling; Jin, Deqiu; Zhang, Qinglian (1988).
1377:
1375:
1373:
1371:
872:
TU is tritium units, or tritium atoms per 10 hydrogen atoms.
1811:
1767:
441:
1368:
1121:"Reference Sheet for International Measurement Standards"
1103:"Reference Sheet for International Measurement Standards"
16:
Standard defining the isotopic composition of ocean water
1802:
ITS-90 – Swedish
National Testing and Research Institute
1530:
1829:
Scientific data of water – London South Bank University
1396:
1394:
1392:
1390:
1327:
1325:
1300:
1298:
356:{\displaystyle (^{2}\mathrm {H} /^{1}\mathrm {H} )_{x}}
1796:
1518:
779:, are used to calibrate isotope-measuring equipment.
615:, the IAEA defined the delta scale with SLAP at −55.5
310:
134:
1626:
1493:
1491:
1489:
1487:
1485:
1483:
1481:
1387:
1322:
1295:
1285:
1283:
1158:
Commission on Isotopic Abundances and Atomic Weights
463:
Commission on Isotopic Abundances and Atomic Weights
1751:
1749:
1554:
1542:
1430:
1358:
1356:
1354:
1352:
1406:
1232:Ferronsky, V. I.; Polyakov, V. A. (6 March 2012).
1137:. International Atomic Energy Agency. August 2007.
355:
292:
1644:
1614:
1602:
1590:
1578:
1566:
1478:
1466:
1454:
1442:
1418:
1280:
1231:
1835:
1746:
1512:
1349:
1337:
1310:
1126:. International Atomic Energy Agency. July 2017.
1057:
810:International Committee for Weights and Measures
798:International Committee for Weights and Measures
659:, measured on 16 September 1976, about 1 in 2.67
93:of the temperature of specifically VSMOW at its
1270:Journal of Physical and Chemical Reference Data
804:as 1/273.16 of the absolute temperature of the
777:National Institute of Standards and Technology
714:On 6 July 2007, the tritium concentration was
1166:"Atomic Weights of the Elements: Review 2000"
1143:"Atomic Weights of the Elements: Review 1993"
1132:"Reference Sheet for Reference Material GISP"
994:
812:specified in 2005 that the definition of the
383:
109:The original container of VSMOW (then called
1824:Temperature Sensors – information repository
1536:
1210:National Institute of Science and Technology
1038:
766:
562:, measured on 16 September 1976, about 1 in
1702:. October 2005. p. 235. Archived from
1381:
1017:
791:
612:
450:
1770:"Determinations of the Boltzmann constant"
1183:
1797:International Atomic Energy Agency – IAEA
1666:Bureau International des Poids et Mesures
1524:
1186:Rapid Communications in Mass Spectrometry
1077:
1058:Hagemann, R.; Nief, G.; Roth, E. (1970).
959:
886:
800:(CIPM) established the definition of the
505:All measurements are reported with their
139:
100:
1238:. Springer Science & Business Media.
832:, the kelvin is defined in terms of the
104:
65:(H) atoms instead of the usual, lighter
846:International Temperature Scale of 1990
1836:
1412:
1331:
1289:
939:
909:
363:denotes the absolute concentration in
1712:
1632:
1400:
1304:
1164:
1141:
968:
868:
866:
78:and 42.8% less deuterium than VSMOW.
1755:
1620:
1608:
1596:
1584:
1572:
1560:
1548:
1497:
1472:
1460:
1448:
1436:
1424:
1362:
1343:
1316:
1216:
1204:
1130:
1119:
1101:
1086:
1812:Scripps Institution of Oceanography
1235:Isotopes of the Earth's Hydrosphere
890:Earth and Planetary Science Letters
693:
376:Scripps Institution of Oceanography
13:
1095:International Atomic Energy Agency
1050:Science Bulletin (English Edition)
863:
438:International Atomic Energy Agency
419:California Institute of Technology
413:= 8‰, i.e., an enrichment of 0.8%.
339:
322:
256:
239:
212:
195:
148:
48:International Atomic Energy Agency
14:
1870:
1790:
406:= 50‰, i.e., an enrichment of 5%;
1225:United States Geological Service
942:"Discontinuance of SMOW and PDB"
536:, about 1 in 6420 hydrogen atoms
20:Vienna Standard Mean Ocean Water
1761:
1732:
1718:
1689:
1650:
1259:"Thermophysical Properties of D
998:Geochimica et Cosmochimica Acta
761:
500:
394:called NBS-1 (sampled from the
1513:Hagemann, Nief & Roth 1970
1251:
602:, about 1 in 2640 oxygen atoms
425:in their possession satisfied
344:
312:
261:
229:
217:
185:
1:
1645:Ferronsky & Polyakov 2012
1206:"Kelvin: Present Realization"
988:10.1126/science.133.3467.1833
940:Coplen, Tyler B. (May 1995).
588:, about 1 in 499 oxygen atoms
1244:
1011:10.1016/0016-7037(53)90051-9
903:10.1016/0012-821X(76)90115-1
392:National Bureau of Standards
7:
1079:10.3402/tellusa.v22i6.10278
839:
710:, (Compare −428‰ for SLAP.)
384:Epstein & Mayeda (1953)
113:) collected by Harmon Craig
10:
1875:
1807:ITS-90 – Omega Engineering
1173:Pure and Applied Chemistry
1150:Pure and Applied Chemistry
920:Pure and Applied Chemistry
879:
469:of SLAP is −55.5‰ and the
417:Later, researchers at the
910:Coplen, Tyler B. (1994).
767:Reporting isotopic ratios
856:
792:Temperature measurements
636:, about 1 in 11230 atoms
611:Based on the results of
512:
1775:Comptes Rendus Physique
933:10.1351/pac199466020273
830:2019 revision of the SI
733:
689:, about 1 in 3700 atoms
634:δ := −428.5 ± 0.4‰
606:
1849:Environmental isotopes
1726:"Resolution 10 - BIPM"
1053:] (19): 1610–1613.
682:, about 1 in 528 atoms
357:
294:
114:
101:History and background
1854:Chemical oceanography
358:
295:
108:
61:, which contains two
1709:on November 2, 2006.
507:standard uncertainty
308:
132:
89:was specified to be
83:redefinition in 2019
982:(3467): 1833–1834.
851:Properties of water
170: (in ‰)
1844:Nuclear technology
1817:2013-06-07 at the
1675:on August 22, 2017
1160:: 2423–2444. 1994.
834:Boltzmann constant
613:Gonfiantini (1978)
451:Gonfiantini (1978)
353:
290:
115:
52:reference material
1647:, pp. 52–53.
1026:(5645): 534–536.
773:Pee Dee Belemnite
687:δ = −28.86 ± 0.1‰
519:mass spectroscopy
423:Potsdam Sandstone
271:
267:
171:
164:
28:isotopic standard
1866:
1784:
1783:
1765:
1759:
1753:
1744:
1743:
1736:
1730:
1729:
1722:
1716:
1710:
1708:
1701:
1693:
1687:
1686:
1681:
1680:
1674:
1668:. Archived from
1663:
1654:
1648:
1642:
1636:
1630:
1624:
1618:
1612:
1606:
1600:
1594:
1588:
1582:
1576:
1570:
1564:
1558:
1552:
1546:
1540:
1534:
1528:
1522:
1516:
1510:
1501:
1495:
1476:
1470:
1464:
1458:
1452:
1446:
1440:
1434:
1428:
1422:
1416:
1410:
1404:
1398:
1385:
1382:Gonfiantini 1978
1379:
1366:
1360:
1347:
1341:
1335:
1329:
1320:
1314:
1308:
1302:
1293:
1287:
1278:
1277:
1267:
1255:
1239:
1228:
1222:
1213:
1201:
1198:10.1002/rcm.4449
1180:
1170:
1161:
1147:
1138:
1136:
1127:
1125:
1116:
1114:
1107:
1098:
1092:
1083:
1081:
1054:
1035:
1032:10.1038/271534a0
1014:
991:
965:
963:
961:10.1038/375285a0
936:
916:
906:
873:
870:
824:
820:
750:= −24.66 ± 0.09‰
729:
727:
721:
719:
709:
694:VSMOW2 and SLAP2
688:
681:
680:δ := −55.5‰
677:
675:
671:
662:
658:
656:
652:
646:
644:
635:
631:
629:
601:
599:
587:
585:
581:
569:
567:
561:
559:
555:
549:
547:
535:
533:
493:
472:
468:
432:
362:
360:
359:
354:
352:
351:
342:
337:
336:
331:
325:
320:
319:
299:
297:
296:
291:
283:
279:
272:
270:
269:
268:
265:
259:
254:
253:
248:
242:
237:
236:
226:
225:
224:
215:
210:
209:
204:
198:
193:
192:
182:
172:
169:
167:
166:
165:
162:
160:
151:
145:
144:
125:may be given as
92:
1874:
1873:
1869:
1868:
1867:
1865:
1864:
1863:
1834:
1833:
1819:Wayback Machine
1793:
1788:
1787:
1766:
1762:
1754:
1747:
1738:
1737:
1733:
1724:
1723:
1719:
1706:
1699:
1695:
1694:
1690:
1678:
1676:
1672:
1661:
1655:
1651:
1643:
1639:
1631:
1627:
1619:
1615:
1607:
1603:
1595:
1591:
1583:
1579:
1571:
1567:
1559:
1555:
1547:
1543:
1535:
1531:
1523:
1519:
1511:
1504:
1496:
1479:
1471:
1467:
1459:
1455:
1447:
1443:
1435:
1431:
1423:
1419:
1411:
1407:
1403:, p. 2435.
1399:
1388:
1380:
1369:
1361:
1350:
1342:
1338:
1330:
1323:
1315:
1311:
1307:, p. 1833.
1303:
1296:
1288:
1281:
1265:
1262:
1257:
1256:
1252:
1247:
1242:
1220:
1168:
1145:
1134:
1123:
1112:
1105:
1090:
914:
882:
877:
876:
871:
864:
859:
842:
822:
818:
794:
769:
764:
757:= −12.71 ± 0.1‰
756:
749:
743:= −189.5 ± 1.2‰
742:
736:
725:
723:
722:in VSMOW2, and
717:
715:
708:= −427.5 ± 0.3‰
707:
703:
696:
686:
679:
673:
669:
667:
660:
654:
650:
648:
642:
640:
633:
627:
625:
609:
597:
595:
583:
579:
577:
565:
563:
557:
553:
551:
545:
543:
531:
529:
515:
503:
492:
488:
470:
466:
446:Plateau Station
430:
426:
412:
405:
347:
343:
338:
332:
327:
326:
321:
315:
311:
309:
306:
305:
264:
260:
255:
249:
244:
243:
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232:
228:
227:
220:
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211:
205:
200:
199:
194:
188:
184:
183:
181:
180:
176:
168:
161:
156:
152:
147:
146:
140:
138:
133:
130:
129:
103:
90:
17:
12:
11:
5:
1872:
1862:
1861:
1856:
1851:
1846:
1832:
1831:
1826:
1821:
1809:
1804:
1799:
1792:
1791:External links
1789:
1786:
1785:
1760:
1745:
1731:
1717:
1688:
1649:
1637:
1635:, p. 705.
1625:
1613:
1601:
1589:
1577:
1565:
1563:, p. 1,3.
1553:
1551:, p. 5–6.
1541:
1537:Li et al. 1988
1529:
1525:Baertschi 1976
1517:
1502:
1477:
1465:
1453:
1441:
1439:, p. 1,6.
1429:
1417:
1405:
1386:
1384:, p. 534.
1367:
1348:
1336:
1334:, p. 274.
1321:
1309:
1294:
1279:
1260:
1249:
1248:
1246:
1243:
1241:
1240:
1229:
1227:. 9 July 2020.
1214:
1212:. 8 July 2021.
1202:
1192:(6): 773–776.
1181:
1162:
1139:
1128:
1117:
1115:on 2020-07-29.
1099:
1084:
1055:
1036:
1015:
1005:(5): 213–224.
992:
966:
937:
927:(2): 273–276.
907:
897:(3): 341–344.
883:
881:
878:
875:
874:
861:
860:
858:
855:
854:
853:
848:
841:
838:
793:
790:
768:
765:
763:
760:
759:
758:
754:
751:
747:
744:
740:
735:
732:
712:
711:
705:
695:
692:
691:
690:
683:
664:
637:
608:
605:
604:
603:
589:
571:
570:hydrogen atoms
537:
514:
511:
502:
499:
490:
484:Sea of Galilee
482:in Italy, the
480:Lake Bracciano
429:sandstone/SMOW
428:
415:
414:
410:
407:
403:
350:
346:
341:
335:
330:
324:
318:
314:
302:
301:
289:
286:
282:
278:
275:
263:
258:
252:
247:
241:
235:
231:
223:
219:
214:
208:
203:
197:
191:
187:
179:
175:
159:
155:
150:
143:
137:
102:
99:
15:
9:
6:
4:
3:
2:
1871:
1860:
1857:
1855:
1852:
1850:
1847:
1845:
1842:
1841:
1839:
1830:
1827:
1825:
1822:
1820:
1816:
1813:
1810:
1808:
1805:
1803:
1800:
1798:
1795:
1794:
1782:(1): 129–139.
1781:
1777:
1776:
1771:
1764:
1757:
1752:
1750:
1741:
1735:
1727:
1721:
1714:
1705:
1698:
1692:
1685:
1671:
1667:
1660:
1653:
1646:
1641:
1634:
1629:
1622:
1617:
1610:
1605:
1598:
1593:
1586:
1581:
1574:
1569:
1562:
1557:
1550:
1545:
1538:
1533:
1526:
1521:
1514:
1509:
1507:
1499:
1494:
1492:
1490:
1488:
1486:
1484:
1482:
1474:
1469:
1462:
1457:
1450:
1445:
1438:
1433:
1426:
1421:
1414:
1409:
1402:
1397:
1395:
1393:
1391:
1383:
1378:
1376:
1374:
1372:
1364:
1359:
1357:
1355:
1353:
1345:
1340:
1333:
1328:
1326:
1318:
1313:
1306:
1301:
1299:
1291:
1286:
1284:
1275:
1271:
1264:
1254:
1250:
1237:
1236:
1230:
1226:
1219:
1215:
1211:
1207:
1203:
1199:
1195:
1191:
1187:
1182:
1178:
1174:
1167:
1163:
1159:
1155:
1151:
1144:
1140:
1133:
1129:
1122:
1118:
1111:
1104:
1100:
1097:. March 1984.
1096:
1089:
1085:
1080:
1075:
1071:
1067:
1066:
1061:
1056:
1052:
1051:
1046:
1042:
1037:
1033:
1029:
1025:
1021:
1016:
1012:
1008:
1004:
1000:
999:
993:
989:
985:
981:
977:
976:
971:
970:Craig, Harmon
967:
962:
957:
954:(6529): 285.
953:
949:
948:
943:
938:
934:
930:
926:
922:
921:
913:
908:
904:
900:
896:
892:
891:
885:
884:
869:
867:
862:
852:
849:
847:
844:
843:
837:
835:
831:
826:
815:
811:
807:
803:
799:
796:In 1954, the
789:
786:
780:
778:
774:
752:
745:
738:
737:
731:
702:
701:
700:
684:
676:0.45 ppm
665:
638:
630:0.05 ppm
623:
622:
621:
618:
614:
593:
590:
586:0.45 ppm
575:
572:
541:
538:
534:0.05 ppm
527:
524:
523:
522:
520:
510:
508:
498:
495:
485:
481:
475:
464:
458:
456:
452:
447:
443:
439:
434:
424:
420:
408:
401:
400:
399:
397:
396:Potomac River
393:
389:
385:
381:
377:
373:
368:
366:
348:
333:
328:
316:
287:
284:
280:
276:
273:
250:
245:
233:
221:
206:
201:
189:
177:
173:
157:
153:
141:
135:
128:
127:
126:
124:
120:
112:
107:
98:
96:
88:
84:
79:
77:
72:
68:
64:
60:
55:
53:
49:
45:
41:
37:
33:
29:
25:
21:
1779:
1773:
1763:
1739:
1734:
1720:
1713:CIAAW (2000)
1704:the original
1691:
1683:
1677:. Retrieved
1670:the original
1665:
1652:
1640:
1628:
1623:, p. 1.
1616:
1611:, p. 2.
1604:
1599:, p. 5.
1592:
1587:, p. 3.
1580:
1575:, p. 6.
1568:
1556:
1544:
1532:
1520:
1515:, p. 6.
1500:, p. 3.
1475:, p. 2.
1468:
1463:, p. 4.
1456:
1451:, p. 3.
1444:
1432:
1427:, p. 2.
1420:
1408:
1365:, p. 2.
1346:, p. 1.
1339:
1319:, p. 3.
1312:
1276:(601). 2009.
1273:
1269:
1253:
1234:
1189:
1185:
1176:
1172:
1153:
1149:
1110:the original
1069:
1063:
1048:
1044:
1023:
1019:
1002:
996:
979:
973:
951:
945:
924:
918:
894:
888:
827:
806:triple point
795:
781:
770:
762:Applications
713:
697:
610:
600:0.8 ppm
516:
504:
501:Measurements
496:
476:
459:
444:sample from
435:
416:
387:
372:Harmon Craig
369:
364:
303:
122:
116:
110:
95:triple point
80:
56:
23:
19:
18:
1413:Coplen 1995
1332:Coplen 1994
1290:Coplen 1994
728:1.6 TU
720:1.0 TU
706:SLAP2/VSMOW
657:10 ppm
560:10 ppm
548:3.6 TU
491:SLAP2/VSMOW
71:water cycle
59:heavy water
1838:Categories
1679:2021-01-01
1633:CIAAW 2000
1401:CIAAW 1994
1305:Craig 1961
1072:(6): 712.
1045:科学通报 (英文版)
828:After the
730:in SLAP2.
594:(O / O) –
576:(O / O) –
542:(H / H) –
528:(H / H) –
411:SMOW/NBS-1
404:SMOW/NBS-1
67:hydrogen-1
1859:Standards
1756:NIST 2021
1621:USGS 2020
1609:USGS 2020
1597:IAEA 2017
1585:IAEA 2007
1573:IAEA 2017
1561:IAEA 2017
1549:IAEA 2006
1498:IAEA 2006
1473:IAEA 2006
1461:IAEA 2017
1449:IAEA 2017
1437:IAEA 2017
1425:IAEA 2017
1363:IAEA 1984
1344:IAEA 1984
1317:IAEA 1984
1245:Citations
785:Greenland
645:9 TU
592:Oxygen-17
574:Oxygen-18
526:Deuterium
457:in 1977.
380:San Diego
285:⋅
274:−
266:reference
163:reference
136:δ
76:oxygen-18
63:deuterium
1815:Archived
1065:Tellus A
840:See also
685:O / O –
666:O / O –
663:10 atoms
639:H / H –
624:H / H –
455:ampoules
91:1/273.16
36:hydrogen
32:isotopes
26:) is an
975:Science
880:Sources
540:Tritium
431:= 15.5‰
388:defined
374:of the
46:-based
1156:(22).
1020:Nature
947:Nature
819:250 μK
814:kelvin
802:Kelvin
530:155.76
304:where
111:SMOW-1
87:kelvin
85:, the
44:Vienna
40:oxygen
1707:(PDF)
1700:(PDF)
1673:(PDF)
1662:(PDF)
1266:(PDF)
1221:(PDF)
1169:(PDF)
1146:(PDF)
1135:(PDF)
1124:(PDF)
1113:(PDF)
1106:(PDF)
1091:(PDF)
1047:[
915:(PDF)
857:Notes
823:50 μK
653:0.09)
649:(3.74
626:89.02
596:379.9
556:0.36)
552:(1.85
513:VSMOW
24:VSMOW
755:GISP
753:δ O
748:GISP
746:δ O
741:GISP
739:δ H
734:GISP
724:27.6
607:SLAP
564:5.40
544:18.5
442:firn
409:δ O
402:δ H
288:1000
38:and
1194:doi
1074:doi
1028:doi
1024:271
1007:doi
984:doi
980:133
956:doi
952:375
929:doi
899:doi
716:3.5
672:.91
670:893
641:374
582:.20
580:005
427:δO
378:in
54:.
34:of
1840::
1780:20
1778:.
1772:.
1748:^
1682:.
1664:.
1505:^
1480:^
1389:^
1370:^
1351:^
1324:^
1297:^
1282:^
1274:13
1272:.
1268:.
1263:O"
1223:.
1208:.
1190:24
1188:.
1177:75
1175:.
1171:.
1154:66
1152:.
1148:.
1093:.
1070:22
1068:.
1062:.
1043:.
1022:.
1001:.
978:.
950:.
944:.
925:66
923:.
917:.
895:31
893:.
865:^
825:.
704:δH
678:,
661:×
647:=
632:,
568:10
550:=
521:.
489:δH
471:δH
467:δO
433:.
367:.
97:.
1758:.
1728:.
1715:.
1539:.
1527:.
1415:.
1292:.
1261:2
1200:.
1196::
1082:.
1076::
1034:.
1030::
1013:.
1009::
1003:4
990:.
986::
964:.
958::
935:.
931::
905:.
901::
726:±
718:±
674:±
668:1
655:×
651:±
643:±
628:±
617:‰
598:±
584:±
578:2
566:×
558:×
554:±
546:±
532:±
365:x
349:x
345:)
340:H
334:1
329:/
323:H
317:2
313:(
300:,
281:)
277:1
262:)
257:H
251:1
246:/
240:H
234:2
230:(
222:x
218:)
213:H
207:1
202:/
196:H
190:2
186:(
178:(
174:=
158:/
154:x
149:H
142:2
123:x
119:‰
22:(
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