Extensive archives of volcanic history are available from ice cores recover
ed from the Antarctic and Greenland ice sheets that receive and preserve su
lfuric acid fallout from explosive volcanic eruptions. The continuous, deta
iled (average 1.2 samples per year) sulfate measurements of a 200-m ice cor
e from a remote East Antarctica site (plateau Remote) provide a record of S
outhern Hemisphere volcanism over the last 4100 years. This extends the vol
canic record beyond the last 1000 years covered by previous Antarctic ice c
ores. An average of 1.3 eruptions per century is recorded in East Antarctic
snow during the last 4100 years. The record shows that on average eruption
s have been more frequent and more explosive during the most recent 2000 ye
ars than in the previous 2100 years, intervals up to 500 years are observed
in which few explosive volcanic signals are detected. These periods includ
e 2000-1500 B.C. (no eruptions), 500-1 B.C. (two eruptions), and 700-1200 A
.D, (two eruptions). This new Plateau Remote volcanic record is compared wi
th those from previous Antarctic ice cores covering the last 1000 years. In
terms of dates for volcanic events, the new record is in excellent agreeme
nt with the earlier records. However, significant discrepancies are found b
etween these records in relative signal magnitude (volcanic flux) of severa
l well-known events. The discrepancies among the records may be explained b
y the differences in the glaciology at the ice core sites, analytical techn
iques used for sulfate and sulfuric acid measurement, ana me selection of d
etection thresholds for volcanic signals. Comparison with Greenland ice cor
e volcanic records indicates that during the last millennium, nine large, l
ow-latitude eruptions contributed significant amounts of volcanic aerosols
to the atmosphere of both hemispheres, potentially affecting global climate
. In contrast, only one or possibly two such eruptions are found in the fir
st millennium A.D.