The postdiluvian patriarchs

Only the age at the birth of the son and the remaining years are mentioned for the postdiluvian patriarchs. The age at which they died can easily be calculated. Again the figures vary depending on the texttype.

Texttype	Masoretic			Septuagint			Samaritan
Name	Son	Years	Died	Son	Years	Died	Son	Years	Died
Noah	502	448	950	502	448	950	502	448	950
Shem	100	500	600	100	500	600	100	500	600
Arphaxad	35	403	438	135	430	565	135	303	438
Shelah	30	403	433	130	330	460	130	303	433
Eber	34	430	464	134	370	504	134	270	404
Peleg	30	209	239	130	209	339	130	109	239
Reu	32	207	239	132	207	339	132	107	239
Serug	30	200	230	130	200	330	130	100	230
Nahor	29	119	148	79	129	208	79	69	148
Terah	70	135	205	70	135	205	70	75	145

The figures for Terah are to his first son. Genesis 12 and Acts 7 imply that Abram was 75 at Terah's death and therefore Terah was 130 when Abram was born, so the year in which Abram was born is 75 years prior to Terah's death.

So we can calculate the year of the flood, the year in which Abram was born and the time elapsed.

Texttype	Masoretic			Septuagint			Samaritan
Period	Flood	Gap	Abram	Flood	Gap	Abram	Flood	Gap	Abram
	1656	352	2008	2242	1132	3374	1307	942	2249

Again I prefer the Masoretic. There seems to be a rationale for lengthening the times so as to make one's culture ancient, but to shorten the timeframe would seem unlikely. As there is no summary age as there is in Genesis 5, the fact of the systematic change in Genesis 5 and the frequent difference of 100 years suggests this was conscious, not accidental.

If the Masoretic is original, then the Samaritan has added years till the year of the first child but subtracted them for the remaining years leaving the total calculated age the same even though this is not given in Scripture. The exceptions being Eber and Nahor. The interesting thing about Eber is that the age after the son was born is 100 years less than the Septuagint. Was there are further Hebrew text which gave 370 years to Eber after his son was born?

Explaining the derivation of the Septuagint is difficult. Arphaxad, Salah and Eber don't appear to derive from the Masoretic at all. A smoothing effect (so that the ages drop off steadily from 900 years) is not clearly apparent and is an inadequate explanation.

If the Masoretic is correct we have the situation where Abram potentially could have known his ancestors. Abram was born in 2008 AM. Note the year of death.

Name	Birth	Death
Noah	1056	2006
Shem	1558	2158
Arphaxad	1658	2096
Shelah	1693	2126
Eber	1723	2187
Peleg	1757	1996
Reu	1787	2026
Serug	1819	2049
Nahor	1849	1997
Terah	1878	2083
Abram	2008	2183

Of Abram's 10 ancestors following the Flood, 7 of them were alive at his birth. Noah died 2 years before Abram was born. And Peleg and Nahor also died prior to his birth. The others were all alive. Shem, who had seen the Flood, only died 25 years before Abram, Abram would have been 150 years old and Isaac 50. Eber, from whom the Hebrews derive their name, outlived Abram!