Record Of Explosive Volcanism Research Articles

The trace-element composition of a Polish stalagmite: Implications for the use of speleothems as a record of explosive volcanism

Identification of volcanic signals preserved in paleoenvironmental records can provide key insights into the timing and consequences of explosive volcanism. Yet the eruption record is incomplete and this confounds our ability to link volcanic eruptions to their impacts on climate and environments. Studies have suggested that stalagmite records can help to address these gaps, through the identification of transient geochemical variability associated with incorporation of elements derived from erupted material. However, the utility of stalagmites for tracing volcanism is poorly constrained globally. Here, we present a high-resolution geochemical dataset for stalagmite NIED08–05 from Niedźwiedzia Cave (Poland). We do this with two primary aims: (1) to test the suitability of NIED08–05 as a record of volcanism since 3 ka BP, and (2) to ascertain whether stalagmites grown in temperate regions preserve volcanic signals with success comparable to those grown in tropical regions. We find transient enrichments of 16 trace elements and the rare-earth-elements Y, La, Nd, which coincide with the timing of some known eruption events. Using Principal Component Analysis (PCA) we find that elements atypically incorporated into calcite (e.g., Fe) co-vary. Similarly, filtering PC1 (17% of the dataset variability) for high magnitude deviations from a baseline signal yields tentative agreement between PC scores and some known large eruptions with tephra found in Poland. We use our analysis to discuss the complexities involved in associating volcanic signals with stalagmite chemistry in temperate regions far from the source of large eruptions. The transport pathway from volcanic source to stalagmite growth surfaces includes the complex Niedźwiedzia Cave hydrological system and is influenced by dense forest above the cave site. Together these factors increase the potential for attenuation of volcanic-derived chemical signals prior to reaching the stalagmite, and so make it difficult to unambiguously link trace element enrichments in NIED08–05 to volcanic eruptions. Our results provide strong evidence that in a temperate depositional environment far from active volcanoes, climate and hydrology conspire to mute the strength of volcanic geochemical signals. Therefore, this work provides important incentives for future research in this area by highlighting that stalagmites grown in a comparatively simple hydrological regime and grown in caves overlain by thin vegetation and soil cover , may preserve volcanic signatures with greater success than those grown in temperate environments.

A detailed 2840 year record of explosive volcanism in a shallow ice core from Dome A, East Antarctica

AbstractA detailed history of volcanism covering the last 2840 years is reconstructed from the top 100.42 m of a 109.91 m ice core from Dome A (DA2005 ice core), East Antarctica. Using two known volcanic stratigraphic markers, the mean accumulation rate during the period AD 1260-1964 is found to be 23.2 mmw.e. a-1, consistent with the previously reported accumulation rate at Dome A. This mean accumulation rate is used to date the entire core. Volcanic eruptions in the period 840 BC-AD1998 are detected as outstanding sulphate events. Seventy-eight eruptions are identified, with a mean of 2.7 eruptions per century. Comparisons with previous Antarctic ice-core volcanic records are made to assess the quality of this new DA2005 record. In terms of dates for volcanic events, the DA2005 record is in good agreement with previous records in the second millennium ad (ad 1000-1998). A series of volcanic signatures found in both the DA2005 record and several other Antarctic ice-core records in the first millennium ad (ad 1-1000) appear to validate the DA2005 record during this time period. For the older periods, direct comparisons are difficult between the DA2005 record and other Antarctic ice-core records due to the lack of well-dated stratigraphic horizons.

A 780-year record of explosive volcanism from DT263 ice core in east Antarctica

Ice cores recovered from polar ice sheet received and preserved sulfuric acid fallout from explosive volcanic eruptions. DT263 ice core was retrieved from an east Antarctic location. The ice core is dated using a combination of annual layer counting and volcanic time stratigraphic horizon as 780 years (1215–1996 A.D.). The ice core record demonstrates that during the period of approximately 1460–1800 A.D., the accumulation is sharply lower than the levels prior to and after this period. This period coincides with the most recent neoglacial climatic episode, the “Little Ice Age (LIA)”, that has been found in numerous Northern Hemisphere proxy and historic records. The non-sea-salt SO 4 2− concentrations indicate seventeen volcanic events in DT263 ice core. Compared with those from previous Antarctic ice cores, significant discrepancies are found between these records in relative volcanic flux of several well-known events. The discrepancies among these records may be explained by the differences in surface topography, accumulation rate, snow drift and distribution which highlight the potential impact of local glaciology on ice core volcanic records, analytical techniques used for sulfate measurement, etc. Volcanic eruptions in middle and high southern latitudes affect volcanic records in Antarctic snow more intensively than those in the low latitudes.

A 12,000 year record of explosive volcanism in the Siple Dome Ice Core, West Antarctica

Air mass trajectories in the Southern Hemisphere provide a mechanism for transport to and deposition of volcanic products on the Antarctic ice sheet from local volcanoes and from tropical and subtropical volcanic centers. This study extends the detailed record of Antarctic, South American, and equatorial volcanism over the last 12,000 years using continuous glaciochemical series developed from the Siple Dome A (SDMA) ice core, West Antarctica. The largest volcanic sulfate spike (280 μg/L) occurs at 5881 B.C.E. Other large signals with unknown sources are observed around 325 B.C.E. (270 μg/L) and 2818 B.C.E. (191 μg/L). Ages of several large equatorial or Southern Hemisphere volcanic eruptions are synchronous with many sulfate peaks detected in the SDMA volcanic ice chemistry record. The microprobe “fingerprinting” of glass shards in the SDMA core points to the following Antarctic volcanic centers as sources of tephra found in the SDMA core: Balenny Island, Pleiades, Mount Berlin, Mount Takahe, and Mount Melbourne as well as Mount Hudson and possibly Mount Burney volcanoes of South America. Identified volcanic sources provide an insight into the poorly resolved transport history of volcanic products from source volcanoes to the West Antarctic ice sheet.

A 4100‐year record of explosive volcanism from an East Antarctica ice core

Extensive archives of volcanic history are available from ice cores recovered from the Antarctic and Greenland ice sheets that receive and preserve sulfuric acid fallout from explosive volcanic eruptions. The continuous, detailed (average 1.2 samples per year) sulfate measurements of a 200‐m ice core from a remote East Antarctica site (Plateau Remote) provide a record of Southern Hemisphere volcanism over the last 4100 years. This extends the volcanic record beyond the last 1000 years covered by previous Antarctic ice cores. 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 eruptions have been more frequent and more explosive during the most recent 2000 years than in the previous 2100 years. Intervals up to 500 years are observed in which few explosive volcanic signals are detected. These periods include 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 with those from previous Antarctic ice cores covering the last 1000 years. In terms of dates for volcanic events, the new record is in excellent agreement with the earlier records. However, significant discrepancies are found between these records in relative signal magnitude (volcanic flux) of several well‐known events. The discrepancies among the records may be explained by the differences in the glaciology at the ice core sites, analytical techniques used for sulfate and sulfuric acid measurement, and the selection of detection thresholds for volcanic signals. Comparison with Greenland ice core volcanic records indicates that during the last millennium, nine large, low‐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 first millennium A.D.