Vera Ponomareva

Institute Of Volcanology And Seismology, Russian Academy of Sciences

In the Nikolaevka-1 quarry (53°05’17.45»N, 158°21’26.28»E), sequence of ash horizons buried in lake sediments formed about 100 thousand years ago were found. Analysis of the composition of volcanic glasses from these tephra allows us to identify for the first time three Late Pleistocene tephras of Avachinsky volcano (21/23, 21/4 and 21/10). In addi...

Polar ice-cores have long been recognised as unrivalled repositories of past volcanic events. Although tephra products from local eruptions tend to dominate these records, improvements in micro-sampling and analytical techniques are uncovering a growing number of cryptotephras erupted from exceptionally distant volcanoes. We present a series of nin...

The distal Pauzhetka tephra, formed by a large caldera-forming volcanic eruption in South Kamchatka, has been identified in eleven recently recovered marine sediment cores based on major and trace element compositions of tephra glass. Ten SO264 cores form a transect along the Emperor Seamount Chain (ESC) in the Northwest (NW) Pacific between ∼50.3°...

We present a continuous ∼6.2 Ma long record of explosive activity from the Northwest Pacific volcanic arcs based on a composite tephra sequence derived from Ocean Drilling Program Sites 882A and 884B, and core MD01‐2416 on the Detroit Seamount. Geochemical fingerprinting of tephra glass using major and trace element analyses and correlations of tep...

The paper presents a reconstruction of geomorphological processes in the Central Kamchatka Depression (CKD) since 30 ka, including the global LGM time. Major geomorphological processes of this period included the evolution of volcanic edifices accompanied by steady tectonic submergence. Glaciers that originated from volcanic edifices were greatly a...

Knowledge of temporal patterns of past explosive eruptions is necessary to understand possible future eruptive behavior. However, volcanic records based on geological reconstructions remain incomplete. This inference is true not only for remote and sparsely populated areas like the Aleutian or Kurile-Kamchatka arcs, but also for Europe, where past...

A number of tephrochronologically correlated and dated sedimentary sections provide evidence for the existence of a giant lake filled the Central Kamchatka depression 30-11 thousand years ago. The lake extent bounded by CKD borders is estimated to be ~10 000 km2. This estimate makes this lake comparable in size to the famous Late Pleistocene glacia...

A tephrochronological study of the core HOR-1 of bottom sediment from Lake Khorlakel, located 24 km northwest of the Elbrus summit, was carried out. The core was 253 cm length. Deposits are represented by interbedding of thin-layered loams and bio-mineral silt. Six intervals of increased content of cryptotephra from 37,000 to 111,000 shards g dry w...

Lakes and bogs in northeastern North America preserve tephra deposits sourced from multiple volcanic systems in the Northern Hemisphere. However, most studies of these deposits focus on specific Holocene intervals and the latest Pleistocene, providing snapshots rather than a full picture. We combine new data with previous work, supplemented by a br...

Volcanic ash layers (tephras) dispersed over large areas may offer important time markers in the geological record provided their age and geochemical fingerprint can be established. Accurately dated and geochemically characterized tephras are essential in correlation of temporally and spatially discontinuous geological records, which is key for pal...

The Kamchatka volcanic arc (NW Pacific) is one of the most productive arcs in the world, known for its highly explosive activity. At the same time, the Kamchatkan record of late Pleistocene explosive eruptions has remained fragmentary. Here we present the first continuous record of Kamchatkan explosive activity between ∼12 and 30 ka, which includes...

The ice-rafted-debris (IRD) record of the open Northwest Pacific points towards the existence of substantial glacial ice on the Northeast Siberian coast during the late Quaternary. However, the scale and timing of glaciation and de-glaciation remains controversial due to the dearth of both onshore and offshore records. Existing IRD data suggests at...

Avachinsky, Kozelsky, and Koryaksky volcanoes form one of the most volcanically active clusters in the Kamchatka volcanic arc and are located in close proximity of the cities of Petropavlovsk-Kamchatsky and Elizovo – the most populated area in Kamchatka. In this paper we report a compilation of new and revised previously published data on the erupt...

Tephra layers produced by volcanic eruptions are widely used for correlation and dating of various deposits and landforms, for synchronization of disparate paleoenvironmental archives, and for reconstruction of magma origin. Here we present our original database TephraKam, which includes chemical compositions of volcanic glass in tephra and welded...

The generation of reliable age models for palaeoenvironmental and archaeological records in the Eurasian Arctic is often problematic when using conventional dating techniques. Tephrochronology can potentially improve the chronologies of such records and synchronise disparate sedimentary archives. However, to date, systematic tephra studies are lack...

Investigation of active faults is crucial for the seismic hazard assessment and, in the case of volcanic belts, it provides a deeper understanding of the interactions between volcanism and tectonic faulting. In this study, we report the results of the first paleoseismological and tephrochronological investigation undertaken on Holocene faulting in...

This paper presents the first detailed study of a late Pleistocene marine tephra sequence from the NW Pacific, downwind from the Kamchatka volcanic arc. Sediment core SO201‐2‐40, located on the Meiji Rise ~400 km offshore the peninsula, includes 25 tephras deposited within the last 215 ka. Volcanic glass from the tephras was characterized using sin...

TephraKam is database comprising the author’s data on chemical compositions of volcanic glass in tephra and welded tuffs from the Kamchatka volcanic arc. The database contains 7049 major element analyses obtained by electron microprobe and 738 trace element analyses obtained by laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS)...

Tephra layers produced by volcanic eruptions are widely used for correlation and dating of various deposits and landforms, for synchronization of disparate paleoenvironmental archives, and for reconstruction of magma origin. Here we present our original database TephraKam, which includes chemical compositions of volcanic glass in tephra and welded...

Tephra layers within marine sediments provide information on past explosive eruptions, which is especially important in the case of remote island arcs where data on proximal pyroclastic deposits can be scarce. Three Alaska-Aleutian tephras (labeled Br2, SR2, and SR4) were found in the late Pleistocene-Holocene sediments of the Bering Sea (north Pac...

Correlation of individual tephra layers over large areas permits the assessment of eruption magnitude and synchronization of disparate sedimentary archives. The middle Pleistocene Pauzhetka caldera with a diameter of ~30 km is one of the largest in Kamchatka. Distal tephra from the caldera-forming eruption has, however, never been found, hampering...

Developing chronologies for sediments in the Arctic Ocean and its continental margins is an important but challenging task. Tephrochronology is a promising tool for independent age control for Arctic marine sediments and here we present the results of a cryptotephra study of a Holocene sedimentary record from the Chukchi Sea. Volcanic glass shards...

Deposits and pumice from the 1400 cal BP eruption of Opala volcano record activity that occurred at the explosive-effusive transition, resulting in intermittent, or stop-start, behavior, where explosive activity resumed following a pause. The eruption deposited distinctive, biotite-bearing rhyolite tephra across much of Kamchatka, and its stratigra...

Contiguous sampling of Holocene ice from the NGRIP core, Greenland, has revealed a new rhyolitic cryptotephra that is geochemically identical to the KHG tephra, a widespread marker deposit originating from the Khangar volcano, Kamchatka. This is the first identification of tephra from the Kamchatka Peninsula in Greenland ice and the first finding o...

Ключевская группа вулканов (КГВ) располагается в северной части Центральной Камчатской депрессии (ЦКД) и является одной из самых крупных и наиболее активных вулканических структур на Камчатке и в мире. В южной части КГВ находится позднеплейстоцен-голоценовый Толбачинский массив, который извергался неоднократно в течение голоцена и исторического вре...

New paleomagnetic determinations satisfying the up-to-date methodical and instrumental standards of paleomagnetic studies are obtained from the lava flows and volcanic ash of the Northern Group of Kamchatka volcanoes. In the past 4000 years, 12 stratigraphic levels with tephrostratigraphic ages are explored. The obtained directions of the geomagnet...

Geochemically fingerprinted widespread tephra layers serve as excellent marker horizons which can directly link and synchronize disparate sedimentary archives and be used for dating various deposits related to climate shifts, faulting events, tsunami, and human occupation. In addition, tephras represent records of explosive volcanic activity and pe...

We used a new sedimentary record from a small kettle wetland to reconstruct the Late Glacial and Holocene vegetation and fire history of the Krutoberegovo-Ust Kamchatsk region in eastern Kamchatka Peninsula (Russia). Pollen and charcoal data suggest that the Late Glacial landscape was dominated by a relatively fire-prone Larix forest-tundra during...

https://agu.confex.com/agu/fm16/meetingapp.cgi/Paper/189267.

The fullest summary on composition, age and distribution of 23 tephra layers detected and investigated in the Okhotsk Sea Pleistocene-Holocene deposits is presented. Seven tephra layers are surely identified with powerful explosive eruptions of volcanoes of Kamchatka, Kurile and Japanese Islands. For them, the areas of ash falls including which wer...

Widespread ash dispersal poses a significant natural hazard to society, particularly in relation to disruption to aviation. Assessing the extent of the threat of far-travelled ash clouds on flight paths is substantially hindered by an incomplete volcanic history and an underestimation of the potential reach of distant eruptive centres. The risk of...

We advance our own definitions of the following terms: catastrophic volcanic eruption (CE), catastrophic supereruption (CSE), different-rank and different-type episodes and phases of volcanic catastrophism (VC). All eruptions are subdivided into three classes according to the volume and weight of the erupted and transported (juvenile and resurgent)...

The Tolbachik volcanic massif, which comprises two stratovolcanoes, Ostry Tolbachik and Plosky Tolbachik, as well as numerous scoria cones and related lava flows, is one of the largest and most active volcanic areas in Kamchatka. The massif has erupted repeatedly during the Holocene and historical times, but became recognised as a volcano of global...

This review is intended to highlight recent exciting advances in the study of distal (>100 km from the source) tephra and cryptotephra deposits and their potential application for volcanology. Geochemical correlations of tephra between proximal and distal locations have extended the geographical distribution of tephra over tens of millions square k...

e-Fig. 1 Interactive Google Earth electronic map of the Tolbachik monogenetic scoria cones showing the ages, locations and compositions of vents and lava flows. The ages are from Braitseva et al. (1984), based on tephrochronological dating of lava flows with the help of regional marker tephra layers (Table 1). Six age groups were identified and com...

The ~16-ka-long record of explosive eruptions from Shiveluch volcano (Kamchatka, NW Pacific) is refined using geochemical fingerprinting of tephra and radiocarbon ages. Volcanic glass from 77 prominent Holocene tephras and four Late Glacial tephra packages was analyzed by electron microprobe. Eruption ages were estimated using 113 radiocarbon dates...

The Kamchatka Peninsula is home to some of the most frequent and prolific subduction-related volcanic activity in the world, with the largest number of caldera-forming eruptions per length of the volcanic arc. Among those, Gorely volcano has a topographically prominent Late Pleistocene caldera (13 km�12 km, estimated to have produced 4100 km3 of ma...

Ash layers from explosive volcanic eruptions (i.e., tephra) represent isochronous surfaces independent from the environment in which they are deposited and the distance from their source. In comparison to eastern Beringia (non-glaciated Yukon and Alaska), few Plio-Pleistocene distal tephra are known from western Beringia (non-glaciated arctic and s...

Detailed data are discussed on the rate of Holocene horizontal and vertical movements along a fault in the southeastern Kamchatsky Peninsula, which is situated between the converging Aleutian and Kamchatka island arcs. The fault is the northern boundary of the block invading into the peninsula under pressure of the Komandorsky Block of the Aleutian...

Kamchatsky Bay is the northernmost bay at the Pacific Kamchatka coast. It is located at the junction between the Kamchatka segment of the Pacific subduction zone and the dextral transform fault of the western Aleutians. The combination of the subduction and collision processes in this region results in the unique set of tectonic controls influencin...

Ash layers from explosive volcanic eruptions (i.e., tephra) represent isochronous surfaces independent from the environment in which they are deposited and the distance from their source. In comparison to eastern Beringia (non-glaciated Yukon and Alaska), few Plio-Pleistocene distal tephra are known from western Beringia (non-glaciated arctic and s...

We report tephrochronological and geochemical data on early Holocene activity from Plosky volcanic massif in the Kliuchevskoi volcanic group, Kamchatka Peninsula. Explosive activity of this volcano lasted for ~1.5 kyr, produced a series of widely dispersed tephra layers, and was followed by profuse low-viscosity lava flows. This eruptive episode st...

[1] Very few age controls exist for Quaternary deposits over the vast territory of the East Russian Arctic, which hampers dating of major environmental changes in this area and prevents their correlation to climatic changes in the Arctic and Pacific marine domains. We report a newly identified ~177 ka old Rauchua tephra, which has been dispersed ov...

The Kamchatka Peninsula is home to some of the most prolific subduction related volcanic activity in the world. Gorely caldera and its central volcano are located in the rear of its currently active Eastern Volcanic Front. Recent work determined the presence of explosive ignimbrite eruptions sourced from Gorely volcano during the Pleistocene. We st...

A tephrostratigraphic and petrological study of the Chikurachki (1816m)-Tatarinov-Lomonosov volcanic chain (CTL volcanic chain) and Fuss (1772m), located at the southern part of Paramushir Island in the northern Kurile Islands, was carried out to reveal the explosive eruption history during the Holocene and the temporal change of the magma systems...

The dominantly andesitic Shiveluch volcano (Kamchatka) is a highly explosive eruptive center with a magma discharge of ~36 Mt/year, an order of magnitude higher than that typical of island arc volcanoes. Frequent ash plumes from Shiveluch pose hazards to local towns and to dozens of daily airflights. Numerous Shiveluch tephras, once fingerprinted,...

Disequilibrium in the short-lived U-series isotopic system occurs during partial melting, differentiation, and volatile transport; therefore, the U-series decay chain is a unique tool to examine the magnitude and timing of magmatic processes. However, our understanding of U-series fractionation in subduction zones is incomplete. We use published da...

Kamchatka Peninsula is one of the most active volcanic regions in the world. Many Holocene explosive eruptions have resulted in widespread dispersal of tephra-fall deposits. The largest layers have been mapped and dated by the ¹⁴C method. The tephra provide valuable stratigraphic markers that constrain the age of many geological events (e.g. volcan...

Avachinsky volcano is one of the most active volcanoes in the frontal volcanic zone of Kamchatka. Previous studies have recognized two distinct phases in the Holocene eruptive history of Avachinsky: 1) early phase of rare and voluminous andesitic eruptions (7.3-3.5 14C ka BP) and 2) later phase of frequent eruptions of basaltic andesites associated...