Description
The authors "present a varve thickness chronology from glacier-dammed Iceberg Lake [60°46'N, 142°57'W] in the southern Alaska icefields," where "radiogenic evidence confirms that laminations are annual and record continuous sediment deposition from AD 442 to AD 1998," and where "varve thickness increases in warm summers because of higher melt, runoff, and sediment transport." This work revealed that the highest varve thickness values of the entire record ("smoothed with a 40-year lowpass Butterworth filter") were observed in the mid-1970s of the Current Warm Period (CWP). Thereafter, varve thickness values declined to the present. We thus classify this paper as a Level 2 study in which peak warmth of the CWP was greater than peak warmth of Medieval times, although we note that the most recent 40-year filtered value is actually less than the peak 40-year filtered value of Medieval Times.