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1.
E. D. Attanasi 《Natural Resources Research》1998,7(4):271-279
According to the National Research Council’s Committee on Earth Resources the stated goal of the “sustainability” paradigm
is that the economic activity that maintains current well-being not make future generations worse off, either through environmental
degradation or resource depletion. Coal is not “running out” in the United States but the effects of economic deregulation
of electricity generation, new air quality standards (Phase II of the 1990 Clear Air Act Amendments), and continued restructuring
of the coal mining industry will likely stretch lowsulfur coal supplies in the next decade. The paper discusses these forces
and then presents summary coal quality data in the form of grade-cumulative tonnage relationships for major U.S. producing
areas to show where future low-sulfur coal supplies are likely to come from. The final section considers the potential magnitude
of additional demand for low-sulfur coal, alternative compliance strategies, and implications in terms of maintaining economic
efficiency and in terms of the “sustainability paradigm.” 相似文献
2.
The investigations on the organic carbon (OC) of core sediments were carried out in Chongming east tidal fiat (CM) during Scirpus mariqueter growing stage (from April to December 2004) in Yangtze Estuary. The Yangtze River annually transports a runoff discharge of 30,000 m^3/s, carrying about 480 million tons of sediments to the estuarine and coastal area, which formed a great OC pool. In the sampling spots, seven quadrats of 50 cm × 50 cm and five sediments cores of 20 cm deep (40 cm deep in December) were randomly established in order to collect vegetations and core sediments samples during the low tide each month except November. After pretreatment, the core sediments were sieved and their OC contents were measured according to the potassium dichromate method. The results show that the higher surface sediment OC content in summer comes from allochthonous terrigenous particle settlements on the Chongming east middle tidal fiat S. mariqueter zone. In autumn and winter, the decomposing of the defoliated S. mariqueter increases the surface sediments OC content. Settling velocity, sediment temperature and S. mariqueter growth are the main factors that can control the sediment carbon content. Summer is the “carbon losing” period of the tidal fiat sediments, while from September, it changes into the “carbon accumulating” period of sediment OC pool because of the decomposing of dead S. mariqueter community in the sediments. From this alternation of “carbon losing” period and “carbon accumulating” period, we conclude that carbon in the OC pool of the middle tidal fiat S. mariqueter zone sediments mainly comes from the atmospheric carbon rooted by S. mariqueter photosynthesis. 相似文献
3.
A theoretical model of conventional oil production has been developed. The model does not assume Hubbert’s bell curve, an
asymmetric bell curve, or a reserve-to-production ratio method is correct, and does not use oil production data as an input.
The theoretical model is in close agreement with actual production data until the 1979 oil crisis, with an R
2 value of greater than 0.98. Whilst the theoretical model indicates that an ideal production curve is slightly asymmetric,
which differs from Hubbert’s curve, the ideal model compares well with the Hubbert model, with R
2 values in excess of 0.95. Amending the theoretical model to take into account the 1979 oil crisis, and assuming the ultimately
recoverable resources are in the range of 2–3 trillion barrels, the amended model predicts conventional oil production to
peak between 2010 and 2025. The amended model, for the case when the ultimately recoverable resources is 2.2 trillion barrels,
indicates that oil production peaks in 2013. 相似文献
4.
Charles E. UmbanhowarJr Philip Camill Jeffrey A. Dorale 《Journal of Paleolimnology》2011,45(2):151-166
Few studies have assessed the relative importance of landscape, land use history, climate, and regional heterogeneity on lake
ecosystem processes, despite the likelihood that interactions among these factors must be important for controlling lake dynamics.
We used 14 sediment measures from 20 lake cores in a climatically sensitive region of the prairie-forest border in southern
Minnesota to (1) assess relationships between modern lake productivity (Carlson’s Trophic State Index [TSI]), modern land-use,
catchment, and lake morphometry, and (2) contrast regional responses to climatic transitions from the ‘Medieval Climatic Anomaly’(1000–1350)
to the ‘Little Ice Age’ (1350–1800) to ‘Modern’(~1980–1996 AD). TSI was significantly positively correlated with modern sedimentation
rate, and accumulation rates of organic matter (OM), biogenic silica (BSi), and total phosphorus (TP). TSI was not significantly
correlated with “modern” land cover, catchment, or lake morphometry characteristics, but total organic N(N) was negatively
correlated with percent cultivation in the catchment area and negatively correlated with δ15N of bulk organic matter in sediment. Regional, among-lake heterogeneity was high over the past 1,000 years, but Little Ice
Age (LIA) cooling appeared to result in an approximately 20% decline in OM, BSi and TP accumulation, while warming and cultural
eutrophication of the past 150 years corresponded to a 200–400% increase in accumulation rates as well as an 80% increase
in carbonates and a small but significant 10% drop in C/N ratios consistent with greater in-lake productivity. Our results
indicate that climate does have regional effects on lake ecosystems but that among-lake variability is high, reflecting the
importance of local factors and suggesting a need for (1) more explicit definition of what ‘regional’ means, (2) a focus on
degree as well as direction of change, and (3) estimating accumulation rates based on multiple lakes and multiple cores within
lakes. 相似文献
5.
T. I. Kuznetsova I. V. Bychkov A. R. Batuev V. M. Plyusnin G. M. Ruzhnikov A. E. Khmel’nov 《Geography and Natural Resources》2011,32(4):315-322
We outline the methods and results of cartographic analysis and assessment the present state of a large region’s geosystems:
their structural, functional and functional-value characteristics have been revealed. Drawing on the notion of epiformations,
we determined the ecological potential of geosystems at the regional level for nature management purposes. A fragment of the
typological general-purpose interpretation map “Ecological potential of the Baikal region’s geosystems” is presented. 相似文献
6.
The US Geological Survey’s 1995 estimates of domestic undiscovered plus undeveloped natural gas nearly tripled quantities
estimated in its 1989 Assessment. Much of the increase came from selected unconventional resources assessed using the paradigm
of continuous-type accumulations. These include such seemingly unrelated “unconventional” gas occurrences as “tight gas,”
coalbed gas, gas in shales, and deep basin-center gas. Though only a small fraction of the assessed 352 trillion cubic feet
is now economic, the quantity is nevertheless significant. Moreover, the lowest cost resources are close to major gas markets
where competing conventional gas is modest. With continued technological improvements these resources can contribute significantly
to future U.S. gas supply, even without subsidies 相似文献
7.
Jaime Escobar Jason H. Curtis Mark Brenner David A. Hodell Jonathan A. Holmes 《Journal of Paleolimnology》2010,43(4):921-938
Sediment cores from Lakes Punta Laguna, Chichancanab, and Petén Itzá on the Yucatan Peninsula were used to (1) investigate
“within-horizon” stable isotope variability (δ18O and δ13C) measured on multiple, single ostracod valves and gastropod shells, (2) determine the optimum number of individuals required
to infer low-frequency climate changes, and (3) evaluate the potential for using intra-sample δ18O variability in ostracod and gastropod shells as a proxy measure for high-frequency climate variability. Calculated optimum
sample numbers (“n”) for δ18O and δ13C in the ostracod Cytheridella ilosvayi and the gastropod Pyrgophorus coronatus vary appreciably throughout the cores in all three lakes. Variability and optimum “n” values were, in most cases, larger for C. ilosvayi than for P. coronatus for δ18O measurements, whereas there was no significant difference for δ13C measurements. This finding may be explained by differences in the ecology and life history of the two taxa as well as contrasting
modes of calcification. Individual δ18O measurements on C. ilosvayi in sediments from Lake Punta Laguna show that samples from core depths that have high mean δ18O values, indicative of low effective moisture, display lower variability, whereas samples with low mean δ18O values, reflecting times of higher effective moisture, display higher variability. Relatively dry periods were thus consistently
dry, whereas relatively wet periods had both wet and dry years. This interpretation of data from the cores applies to two
important periods of the late Holocene, the Maya Terminal Classic period and the Little Ice Age. δ18O variability during the ancient Maya Terminal Classic Period (ca. 910–990 AD) indicates not only the driest mean conditions
in the last 3,000 years, but consistently dry climate. Variability of δ13C measurements in single stratigraphic layers displayed no relationship with climate conditions inferred from δ18O measurements. 相似文献
8.
Defining the reference state of some perturbed streams and rivers is challenging since their non-altered state is undocumented.
Despite the near-absence of pristine sites in highly anthropogenic areas, information about aquatic communities that existed
prior to human disturbance can be obtained from historic sources. Sediment coring is commonly used in paleolimnology to estimate
past environmental conditions of lakes, but this technique is often not appropriate for studies of lotic systems. An alternative
is to use diatom assemblages present in the guts of fish that were captured in the streams prior to significant human disturbance.
The purpose of the present study was to evaluate the biological integrity of several streams in Ontario and Québec during
the early twentieth century based on “paleo” diatom assemblages extracted from the guts of fish stored in museums. The Eastern
Canadian diatom index (IDEC: Indice Diatomées de l’Est du Canada) was used to evaluate the biological status of “paleo” and
“modern” diatom assemblages. The IDEC shows the position of diatom assemblages on a general pollution gradient. The comparison
of IDEC values calculated for the 1925–1948 and the 2003–2007 periods showed that several streams were severely polluted in
the early 1900s. In general, present water quality has declined compared to the early 1900s. The biological integrity of only
three of the 22 sites has increased. IDEC values were not influenced by the species of fish studied. 相似文献
9.
1 Introduction Oases are unique ecosystems and important residences for our ancestors in arid and semiarid regions of the world, and have deeply been imprinted by human actions, such as Jericho oasis of Jordan Valley, Jarmo oasis of the Euphrates River an… 相似文献
10.
Piero Guilizzoni Aldo Marchetto Andrea Lami Stefano Gerli Simona Musazzi 《Journal of Paleolimnology》2011,45(4):433-445
We propose a palaeolimnological method for inferring past total phosphorus (TP) concentrations in lake water from spectrophotometrically-measured
sedimentary pigments, particularly total carotenoids (TC). Our approach is based on a highly significant statistical correlation
(P < 0.0001) between pigment concentrations (total carotenoids) in the surface sediment of 28 Italian lakes (subalpine, large,
deep, shallow, volcanic) and TP concentrations measured in these lakes at overturn when the core was collected. A transfer
function was developed from this “training” set, and used to estimate past TP concentrations from pigment concentrations in
sediment cores. The results generally agreed with TP values as measured by long-term water quality monitoring programs. Contrasting
results were obtained by a comparison with diatom-inferred TP. While the diatom model showed a tendency to overestimate TP
values higher than 100 μg l−1, the pigment model correctly estimated TP in lakes when TP was <100 μg l−1, but not when lakes were rich in macrophytes. In fact, lakes with extensive populations of aquatic submersed macrophytes
and epiphytes are outliers in terms of the TC versus TP relationship. The root mean square error of prediction of the pigment
model is lower than those derived from certain diatom—based inference models. The predicted and residual values are not related
to the estimated values and their average is not statistically different from zero. Errors were estimated via a ‘leave-one-out’
re-sampling technique. The proposed method permits rapid and relatively inexpensive determination of reference trophic conditions. 相似文献
11.
WANG Xiqin ZHANG Yuan LIU Changming 《地理学报(英文版)》2007,17(3):304-316
In this article the meaning of the quantity and quality of environmental flows of river in dualistic water cycle is discussed, and compared with the meaning of unitary water cycle. Based on the analysis of the relationship between environmental flows of river requirements, the efficiency of water resource usage, the consumption coefficient, and the concentration of waste water elimination, the water quantity and water quality calculation method of the environmental flows of river requirements in dualistic water cycle is developed, and the criteria for environmental flows of river requirements are established, and therefore the water quantity-quality combined evaluation of natural river flows requirements are realized Taking the Liaohe River as a model, the environmental flows of river requirements for Xiliao River, Dongliao River, mainstream Liaohe River, Huntai River and northeast rivers along the coasts of the Yellow and Bohai seas in unitary water cycle are calculated, each taking up 39.3%, 63.0%, 43.9%, 43.3% and 43.5% of runoff respectively. Evaluated according to Tennant recommended flow, the results show that: except Xiliao River is "median", the rest are all upon "good", the Dongliao River is even "very good". The corresponding results in dualistic water cycle are that, the proportion of natural flows for each river is 57.5%, 74.1%, 60.8%, 60.3% and 60.4%; while the combined evaluation results show that: considering "quantity", except Xiliao River, the rest rivers can all achieve the "quantity" criteria of the en- vironmental flows of river requirements, but if considering the aspect of "quality", only Dongliao River can reach the "quality" standard. By water quantity-quality combined evaluation method, only Dongliao River can achieve the criteria. So the water quality is the main factor that determines whether the environmental flows can meet the river ecosystem demands. 相似文献
12.
I. Mazzini C. Faranda M. Giardini C. Giraudi L. Sadori 《Journal of Paleolimnology》2011,45(2):243-256
We present a Holocene record of climate and environmental change in central New York (USA) inferred using lithologic and stable
isotope data from two sediment cores recovered in Cayuga Lake. The record was divided into three intervals: (1) early Holocene
(~11.6–8.8 ka), (2) Hypsithermal (~8.8–4.4 ka), and (3) Neoglacial (~4.4 ka to present). The early Holocene began abruptly,
with rising lake level and relatively deep water. Between ~10.8 and 9.2 ka, cool and dry conditions prevailed at a time of
maximum solar insolation. This anomaly has been referred to as the “post-Younger Dryas climate interval” and lasted ~1,600 years,
the approximate length of one “Bond cycle.” The Hypsithermal was the warmest, wettest and most biologically productive interval
of the Holocene in central New York. The Hypsithermal was characterized by centennial to multi-centennial-scale variability.
The 8.2 ka event is one such variation. The Neoglacial was an interval of generally cooler and dryer conditions, falling lake
levels, and several prominent climate anomalies. At approximately 2.4 ka, δ13C of bulk organic matter increased abruptly by 5‰ as lake level declined, and the lake flora was dominated by Chara sp. during the coldest interval of the Neoglacial. Numerous sediment variables display increased variability ~2.0 ka, which continues
today. Archaeological data from the literature suggest that Native American populations may have been large enough to impact
land cover by about 2.4 ka and we hypothesize that the “Anthropocene” began at about that time in central New York. We also
found paleolimnological evidence for the Medieval Warm Period (~1.4–0.5 ka), which was warmer and wetter than today, and for
the Little Ice Age (~500–150 years ago), a period with temperatures colder than today. 相似文献
13.
Roderick J. Mclntosh Boubacar Hama Diaby Tér’ba Togola 《Natural Resources Research》1997,6(2):111-129
There is a civilization at risk. In the middle of West Africa, just south of the Sahara, where the Niger River spills into
a vast floodplain (the Middle Niger), an indigenous urban civilization emerged around two thousand years ago. The story of
that civilization is just beginning to be uncovered from the thousands of tells (ancient settlement mounds) that litter the
Middle Niger, but archaeologists have until recently been loosing the race with the looters who plunder these sites for ancient
statues and bronze art. The nation of Mali, and the local community of Jenne at the epicenter of this looting recently invented
effective shields for the remains of this civilization, protections against local looters in the employ of a syndicate of
wealthy European antiquities dealers. In the person of the new, democratically-elected archaeologist-President, the nation
has articulated a vision of Mali’s future linked to the preservation of its past. The government has promulgated effective
regulations and education programs, and initiated with the United States the world’s first bilateral import ban between a
major “source” and a major “market” nation. This 1993 bilateral accord has become a prototype for many nations. In that same
year, Mali established a Cultural Mission at Jenne to reinforce local pride in a local past. This local pride, in only a short
period, has turned into a total protection of some 200 sites within a ten-kilometer radius of Jenne. These indigenous actions
have, in less than a decade, transformed the nonrenewable archaeological resources of the Jenne region from surely one of
the world’s most endangered, to a case study in local and national protection 相似文献
14.
A. E. Poberezhnaya A. P. Fedotov T. Ya. Sitnikova M. Yu. Semenov G. A. Ziborova E. L. Otinova A. V. Khabuev 《Journal of Paleolimnology》2006,36(2):133-149
This paper deals with the investigation of the upper 11.6 m portion of a long drill core (KDP-01) taken from the bottom sediments of Lake Khubsugul. Ostracod species and their assemblages recovered from the core were analyzed. The data are compared with the carbonate and sulfate values obtained from bulk sediment, as well as with the flux of the coarse terrigenous fraction (>200 m) from the same core. Based on the previously calculated depth-age sedimentary model, the oldest age of the core studied here is about 230 ka. The four ostracod species recovered in the core are Cytherissa lacustris, Candona lepnevae, Limnocythere inopinata and Leucocythere sp. According to the distribution of those ostracods, we distinguish four main periods, each of about 50 ka long. Based on the ecological requirements of extant ostracods, two assemblages typifying a low water level and high salinity, on the first hand, and another representing freshwater and high lake level are recognized. The first “high salinity” ostracods correspond to “cold” periods as seen globally, while “freshwater” ostracods are associated with interglacials. Ostracod valves are absent during interglacial optima. This may be due to chemical dissolution of calcium carbonate related to organic matter decay at the initial stages of diagenesis, probably because during interglacials, in contrast to glacials, organic matter flux reaching the lake bottom were significantly higher. The periodicity in the development of ostracod species assemblages follows 17, 24 and 47 ka cycles related to orbital forcing. Its diversity is correlated with summer temperature fluctuations in northern altitudes for the past 230 ka. The maximum in species diversity follows the temperature maxima, by about 1.5 and 2 ka. Overall, the data obtained demonstrate a correlation between climatic changes and variations in specific and quantitative ratios of ostracod species during the last 230 ka. 相似文献
15.
Faith S. Coleman 《International Journal of Salt Lake Research》1999,8(1):71-74
A study at the Penrice Soda Products Saltfields revealed that a “weed” blocking siphons in the lower salinity end of the fields
was a bryozoan,Zoobotryon verticillatum (della Chiaje). Further observations showed that this bryozoan grows from early October to mid June, dying off for 3 months
during winter, and that it was commonly found in salinities of up to 56 grams per litre. 相似文献
16.
Robert C. Milici 《Natural Resources Research》2009,18(2):85-94
The production of liquid fuels from coal will very likely become an important part of the hydrocarbon energy mix of the future,
provided that technical and environmental obstacles are overcome economically. The coal industry should be able to handle
a coal-to-liquids (CTL) industry of modest size, using 60–70 million short tons or 54–64 million metric tonnes of coal per
annum, without premature depletion of the country’s coal reserves. However, attempts to use CTL technology to replace all
petroleum imports would deplete the nation’s coal reserves by the end of the century. 相似文献
17.
Quantitative reconstructions of mean July temperatures (T
jul) based on new and previously published pollen-stratigraphical data covering the last 2000 years from 11 lakes in northern
Fennoscandia and the Kola Peninsula are presented. T
jul values are based on a previously published pollen-climate transfer function for the region with a root-mean-square error
of prediction (RMSEP) of 0.99°C. The most obvious trend in the inferred temperatures from all sites is the general decrease
in T
jul during the last 2000 years. Pollen-inferred T
jul values on average 0.18 ± 0.56°C (n = 91) higher than present (where “present” refers to the last three decades based on pollen-inferred T
jul in core-top samples) are indicated between 0 and 1100 AD (2000–850 cal year BP), and temperatures −0.2 ± 0.47°C (n = 78) below present are inferred between 1100 and 1900 AD (850–50 cal year BP). No consistent temperature peak is observed
during the ‘Medieval Warm Period’, ca. 900–1200 AD (1100–750 cal year BP), but the cooler period between 1100 and 1900 AD
(850–50 cal year BP) corresponds in general with the ‘Little Ice Age’ (LIA). Consistently with independent stable isotopic
data, the composite pollen-based record suggests that the coldest periods of the LIA date to 1500–1600 AD (450–350 cal year
BP) and 1800–1850 AD (150–100 cal year BP). An abrupt warming occurred at about 1900 AD and the twentieth century is the warmest
century since about 1000 AD (950 cal year BP).
相似文献
A. E. BjuneEmail: |
18.
Epiphytic diatoms as flood indicators 总被引:1,自引:0,他引:1
Johan A. Wiklund Natalie Bozinovski Roland I. Hall Brent B. Wolfe 《Journal of Paleolimnology》2010,44(1):25-42
The hydroecology of floodplain lakes is strongly regulated by flood events. The threat of climate warming and increasing human
activities requires development of scientific methods to quantify changes in the frequency of short-lived flood events, because
they remain difficult to identify using conventional paleolimnological and monitoring approaches. We developed an approach
to detect floods in sediment records by comparing the abundance and composition of epiphytic diatom communities in flooded
and non-flooded ponds of the Peace-Athabasca Delta (PAD), Canada, that grew on submerged macrophytes (Potamogeton zosteriformis, P.
perfoliatus) and an artificial substrate (polypropylene sheets) during the open-water season of 2005. Analysis of similarity tests showed
that epiphytic diatom community composition differs significantly between flooded and non-flooded ponds. After accounting
for the “pond effect,” paired comparisons of the three substrates determined that variation in community composition between
the artificial substrate and macrophytes was similar to that between the macrophyte taxa. Similarity percentage analysis identified
diatom taxa that discriminate between flooded and non-flooded ponds. The relative abundance of ‘strong flood indicator taxa’
was used to construct an event-scale flood record spanning the past 180 years using analyses of sedimentary diatom assemblages
from a closed-drainage pond (PAD 5). Results were verified by close agreement with an independent paleoflood record from a
nearby flood-prone oxbow pond (PAD 54) and historical records. Comparison of epiphytic diatoms in flooded and non-flooded
lakes in this study provides a promising approach to detect changes in flood frequency, and may have applications for reconstructing
other pulse-type disturbances such as hurricanes and pollutant spills. 相似文献
19.
Catastrophic hurricane history revealed by organic geochemical proxies in coastal lake sediments: a case study of Lake Shelby,Alabama (USA) 总被引:2,自引:0,他引:2
We developed a new method for reconstructing millennia-long hurricane records from coastal environments that uses Organic
Geochemical Proxies (OGPs) of organic carbon and nitrogen concentrations and their δ13C and δ15N compositions. The new method is independent of presence/absence of sand layers and improves significantly the severe-storm
history resolution. The subject of this investigation is a 1.5 m long sediment core raised at 2.8 m water depth from the center
of Lake Shelby, Alabama, a freshwater lake located approximately 250 m from the Gulf of Mexico, from which an overwash sand-layer
based record was previously derived. The core contains two distinct sediment units; an upper 62 cm thick, fine-grained, organic-rich
lacustrine sapropel (gyttja) that shows no visible structures except one sand lamina at 23.7 cm depth, and an underlying 90 cm
thick, organic-poor lagoon/estuary clay unit. The sapropel unit was deposited over a 682 ± 30 cal year time interval (1320–2002 A.D.)
with a mean sedimentation rate of 0.79 ± 0.04 mm/year. Lake Shelby’s water column exhibits two contrasting states based on
water chemistry surveys (i) an “isolated”, stratified, mode under calm weather conditions with a relatively low trophic state,
and (ii) a “flooded” mode occurring during storm surges when nutrient-rich seawater floods the lake. Statistically significant
δ13C and δ15N positive excursions in organic matter, up to maximum values of −25 (‰ PDB) and 4 (‰ Air N2), respectively, are interpreted as geochemical responses to the marine intrusions that fertilize the lake, increase light
availability, and cause eutrophication spikes. Detailed OGPs analyses crossing a sand layer that offers visual evidence of
a catastrophic hurricane overwash event at 1717 A.D. exhibit large δ13C and δ15N positive shifts bounded by rapid returns to base values, thus confirming the validity of the hurricane identification by
the OGPs model. Our data indicate that 11 catastrophic hurricanes hit the Alabama coast over the past 682 years with a rough
recurrence interval of one in 62 years. 相似文献
20.
Geomorphic, lithologhic, and stratigraphic field studies as well as pollen data and mineralogical study have been used to
propose Pliocene and Pleistocene paleogeographic reconstructions of the El’gygytgyn meteorite crater area. The moment of impact
is recorded above the early Pliocene hill denudation plain as a “chaotic horizon” consisting of fragments of impactite rocks.
This chaotic horizon lies between layers of late Pliocene alluvial sediments. During the second half of the late Pliocene,
the region was tectonically active, when the Anadyr lowland was uplifted causing alluvial sediments to accumulate in the basins
to the south of the crater. Regional climatic cooling, which supported the spread of tundra and the formation of permafrost
is characteristically to late Pliocene. The 35–40 m high terrace that roughly follows the 530 m contour interval along the
Enmyvaam River formed during the middle Pleistocene. This terrace represents the maximum lake level. Erosion and incision
of the upper Enmyvaam River increased due to another wave of uplift. Additionally, El’gygytgyn Lake discharge increased causing
lake level to begin to drop in the Middle Pleistocene. Cooling continued, which led to the development of herb-dominated arctic
tundra. middle and late Pleistocene glaciations did not reach the El’gygytgyn lake region. The 9–11 m high lacustrine terrace
was formed around the lake during the late Pleistocene and the 2–3 m high lacustrine terrace formed later during the Holocene.
During the last 5000 years, the lake level has continued to drop as the modern coastline developed.
This is the third in a series of eleven papers published in this special issue dedicated to initial studies of El’gygytgyn Crater Lake and
its catchment in NE Russia. Julie Brigham-Grette, Martin Melles, Pavel Minyuk were guest editors of this special issue. 相似文献