Geochemical ice-core constraints on the timing and climatic impact of Aniakchak II (1628 BCE) and Thera (Minoan) volcanic eruptions

If it is a valid assumption to integrate the Sofular Cave evidence, then this would help more firmly to exclude as plausible some dates for possible volcanic proxy evidence around 1561/1560, 1558, 1555/1554, 1546, 1544, 1539/1538 or 1524 BCE.

“Most importantly, if it is a valid assumption to integrate the Sofular Cave evidence, then this would help more firmly to exclude as plausible some dates for possible volcanic proxy evidence that have been suggested as potentially relevant for the Thera eruption around 1561/1560, 1558, 1555/1554, 1546, 1544, 1539/1538 or 1524 BCE [13,14].”

Two additional volcanic events identified at 1586 BCE (Greenland) and 1550 BCE (Antarctica) are currently considered less likely for Thera based on tephra / hemispheric deposition evidence.

“Two additional volcanic events identified at 1586 BCE (Greenland) and 1550 BCE (Antarctica) are not shown as they are currently considered less likely for Thera based on tephra / hemispheric deposition evidence31, but should be further investigated.”

The Thera eruption might well not be represented by one of the largest sulfur signals in polar ice sheets, and might instead be represented by one of the more modest volcanic signals in the ice or tree-ring records like ~1611/1610 BCE, 1597 BCE, 1586 BCE or 1584 BCE, or might not even offer a clear signal in one or more distant proxy records.

“the Thera eruption might well not be represented by one of the largest, or even larger, sulfur signals in polar ice sheets, and might instead be represented by one of the more modest volcanic, or potentially volcanic, signals in the ice or tree-ring records like one of those ~1611/1610 BCE, 1597 BCE, 1586 BCE or 1584 BCE [13,14], or, indeed, despite its cataclysmic relevance to the southern Aegean”

The most likely 68.3% hpd range in Fig 9, 1606-1589 BCE, does not correspond with most of the possible proxy volcanic eruption signals noted so far in ice-core, tree-ring and other records; only the bristlecone pine minima 1597 BCE overlaps, with other signals just outside this range: 1611/1610 BCE, 1586 BCE and 1584 BCE.

“The most likely 68.3% hpd range in Fig 9, 1606-1589 BCE, does not in fact correspond with most of the possible proxy volcanic eruption signals noted so far in ice-core, tree-ring and other records-only the bristlecone pine minima 1597 BCE overlaps-with the other signals noted in this vicinity just outside this range: 1611/1610 BCE, 1586 BCE and 1584 BCE [12-14, 44, 70].”

Calendar dated ice-core sulfate layers at 1611 BCE, 1562-1555 BCE and c.1538 BCE have been highlighted as possible markers for the Thera eruption.

“Figure 5 also shows calendar dated ice-core sulfate layers at 1611 BCE, 1562-1555 BCE and c.1538 BCE which have been highlighted as possible markers for the Thera eruption31.”

The Thera eruption may not have had a very large sulfur deposition onto Arctic and Antarctic icesheets, nor a particularly large aerosol-related climate impact globally.

“and so, despite its enormous scale, the Thera eruption may not have had a very large sulfur deposition onto Arctic and Antarctic icesheets, nor had a particularly large aerosol-related climate impact globally [13,14,153,154].”

In combination with other recent data and reassessments, this finding removes many past positions or suggestions for the date of the Thera eruption (e.g. mid to later 17th century BCE, 1640s-1620s BCE) as now unlikely or not possible.

“In combination with other recent data and reassessments [14,70,150], this finding removes many past positions or suggestions for the date of the Thera eruption (e.g.several past suggestions for a date in the mid to later 17 th century BCE, 1640s-1620s BCE) as now unlikely or not possible”

The ice-core volcanic eruption signals noted for 1561, 1558, 1555 and 1550 BCE are either barely in, or just outside, the late end tail of the most likely 95.4% range.

“The ice-core volcanic eruption signals noted for 1561, 1558, 1555 and 1550 BCE [14] are either barely in, or just outside, the (poorly defined) late end tail of the most likely 95.4% range.”

The spacings in the Mo record do not suggest any likely pattern of associations with the major eruptions of the period, and there is just one major peak within the available record, suggesting a specific, local source.

“The spacings do not suggest any likely pattern of associations with the major eruptions of the period as listed in [14] at Table 2, and there is just the one major peak within the available record, suggesting again a specific, local, source.”

The spacings in the Sofular Cave Br record do not suggest any clear or systematic associations with the major volcanic eruptions of the period.

“The spacings do not suggest any clear or systematic associations with the major volcanic eruptions of the period as listed in [14] at Table 2 (even moving the dates systematically up or down within the ±25 years dating error).”