Elgygytgyn is a crater lake in Chukotka. Located on the Anadyr plateau, in the Anadyr region, about 390 kilometers north-west of Anadyr. The name is translated from Chukchi as "white lake".
Location and Overview
Lake Elgygytgyn, also known as El'gygytgyn,
is a remote crater lake situated in the Anadyr Plateau within the Anadyr
Highlands on the Chukchi Peninsula in northeast Siberia, Russia. It lies
in the Anadyrsky District of the Chukotka Autonomous Okrug,
approximately 150 km southeast of Chaunskaya Bay and about 100 km north
of the Arctic Circle. The lake's geographic coordinates are centered at
67°30′ N and 172°05′ E, placing it in a far northeastern region of
Russia characterized by extreme isolation and harsh Arctic conditions.
The name "Elgygytgyn" derives from the Chukchi language, meaning "white
lake," likely referring to its often ice-covered surface.
The lake
occupies a meteorite impact crater, making it a unique geographical
feature in the Arctic landscape. This setting provides a natural basin
that has preserved a continuous record of environmental and climatic
changes over millions of years.
Formation and Geology
The lake
formed within an impact crater created approximately 3.6 million years
ago during the Pliocene epoch, when a meteorite struck the region. This
event occurred in the Late Cretaceous Okhotsk-Chukotka Volcanic Belt
(OCVB), specifically targeting siliceous volcanic rocks of the Pykarvaam
Series, dated around 88.5 ± 1.7 million years old. The crater is the
only known terrestrial impact structure in such highly siliceous
volcanic targets, distinguishing it geologically from other craters.
The impact resulted in a circular depression with a rim diameter of
about 18 km, surrounded by an uplifted ridge. The crater walls descend
steeply to a flat-bottomed bowl, with the rim rising generally 180 m
above the lake level and 140 m above the surrounding terrain, though
partially eroded in the southeastern sector. An outer ring feature,
about 14 m high, is present at roughly 1.75 crater radii from the
center. The structure includes a complex network of radial and
concentric faults, with fault density highest near the rim base and
decreasing outward to about 2.7 crater radii.
Beneath the lake,
seismic data reveal a central uplift approximately 2 km wide, buried
under post-impact sediments, and centered relative to the crater rim
rather than the lake itself. The basin contains 360–420 m of sedimentary
fill near the center, overlain by 100–400 m of allochthonous breccia.
Impactites recovered from drilling include polymict lithic breccias
(suevites) with shocked minerals, brecciated volcanic sequences, and
monomict breccias of rhyodacitic ignimbrite. The pre-impact stratigraphy
consists of layered rhyolitic ignimbrites, tuffs, lavas, and minor
andesitic and basaltic units, dipping gently eastward.
The region
avoided widespread glaciation during the Pleistocene Ice Age, which
preserved the crater's rocks and allowed up to 400 m of undisturbed lake
sediments to accumulate, offering a rare continuous paleoclimate
archive. This includes evidence of polar amplification, super
interglacials with elevated temperatures and precipitation, and warmer
mid-Pliocene conditions.
Physical Characteristics
Lake
Elgygytgyn has a nearly circular shape, with a diameter of 12 km,
matching its maximum length and width. Its surface area spans 110 km²,
and it reaches a maximum depth of 174 ± 2 m, with the lake bowl being
relatively flat. The lake is slightly off-center within the crater,
shifted toward the northwest. Lacustrine terraces at elevations of 80 m,
60 m, 40 m (most prominent on the western and northwestern sides), and
1–3 m above the current lake level indicate historical fluctuations in
water levels.
The lake sits at an elevation of 492 m above sea level.
Its waters are ultra-oligotrophic, meaning they are nutrient-poor and
clear, with temperatures typically just above freezing.
Hydrology
The lake's catchment area covers 293 km², fed by around 50 small
tributaries that drain the surrounding crater rim and highlands. It has
a single outlet, the Enmyvaam (or Enmivaam) River, which exits to the
southeast through a cut in the crater rim and flows 230 km as a
tributary of the Belaya River in the Anadyr River basin. This
hydrological setup contributes to the lake's stability, with minimal
external influences.
The ecosystem supports specialized fauna,
including three species of char fish, two of which (Salvelinus elgyticus
and Salvethymus svetovidovi) are endemic, along with over a dozen
endemic diatom species.
Climate and Environment
The climate
around Lake Elgygytgyn is extremely cold and Arctic, with the lake
ice-covered for about 9–10 months of the year, from October to July. In
some summers, the ice may not fully thaw, leading to prolonged periods
of darkness and cold for aquatic life. The short growing season supports
Arctic tundra vegetation, dominated by low-lying plants, mosses, and
lichens in the surrounding valleys and ridges.
The environment is
pristine and undisturbed, with no human settlements nearby, emphasizing
its role as a natural laboratory for studying long-term climate
dynamics.
Surrounding Terrain
The lake is encircled by the
crater's uplifted rim and a network of ridges and vegetated valleys. The
terrain outside the crater slopes gently, contrasting with the steep
inner crater walls. The broader Anadyr Highlands feature rolling
plateaus and volcanic remnants from the OCVB, with the crater integrated
into this landscape. Vegetation is sparse tundra, adapted to permafrost
and wind-swept conditions, with bare rocky areas visible in satellite
imagery.
Geographical Significance
Lake Elgygytgyn's geography
is of immense scientific value due to its undisturbed sedimentary
record, spanning 3.6 million years, which has revealed insights into
Arctic climate variability, including periods of intense warming and
precipitation changes. As one of the few unglaciated sites in the
Arctic, it serves as a benchmark for understanding global climate
patterns, polar amplification, and biodiversity in extreme environments.
International drilling projects, such as the 2009 ICDP effort, have
further highlighted its role in paleoclimatology and impact geology.
Three types of char (palii) live in water layers of Lake Elgygytgyn of different depths: large and predatory Boganid char (below), as well as planktivorous smallmouth char, and long-feather char (above). Svetovidov's long-finned char (Salvethymus svetovidovi) is a narrow-range fish species, described in 1990, not found anywhere outside this lake. In order to protect it, the lake was declared a natural monument of Chukotka.
The lake is a water-filled depression in
the earth's surface that was formed about 3.6 million years ago.
The basin of the lake is of meteorite origin and is an impact
crater (astroblem) filled with water and sediments. For a long time,
there was an assumption that this is a volcanic crater, but it was
refuted by the results of drilling the bottom of the lake in 2008.
The crater is located in acid rocks of volcanic origin (including
tuffs) and at the time of research was the only impact crater known
on Earth in rocks of this type.
The first lake
was described by Sergei Vladimirovich Obruchev in the 1930s. In his
works, this lake was called Elgydhyn.
In the 1950s, research
was carried out by employees of the Anadyr permafrost station. The
depths were measured, the temperature was measured, water samples
were taken, the lake shoreline was surveyed, rock samples were taken
from wells and outcrops, samples of lake bottom sediments, plankton
samples, control samples of lake water.
In 1984, an
expedition to the lake was undertaken by the Magadan writer Albert
Miftakhutdinov, dedicating it to the 50th anniversary of Oleg
Kuvaev.
In the 1980s-1990s, specialists from the
North-Eastern Complex Research Institute (Magadan) worked on the
lake. Many articles and books have been published on the results of
the expeditions.
In 1998, 2000, 2003, 2008 and 2009,
international expeditions went to the lake: researchers from the
Institute of Geology and Geophysics of the University of Leipzig,
the Institute for Polar and Marine Research named after I. Alfred
Wegener (Germany), Massachusetts and Alaska Universities (USA),
Russian scientists from the Arctic and Antarctic Research Institute
of Roshydromet (St. Petersburg) and the North-Eastern Complex
Research Institute of the Far Eastern Branch of the Russian Academy
of Sciences. The international project "Paleoclimate of Lake
Elgygytgyn" is funded by the USA and Germany.
In August 2020,
employees of the Kronotsky Nature Reserve, Moscow State University
named after I. MV Lomonosov, Institute of Ecology and Evolution. A.
N. Severtsov RAS and Institute of Developmental Biology named after
NK Koltsov RAS, within the framework of a scientific expedition,
conducted research on the ichthyofauna of Lake Elgygytgyn.
Scientists also collected hydrobiological materials - samples of
invertebrates that inhabit the bottom of the lake and the water
column. Instrumental complex measurements of the parameters of the
fish habitat have been carried out. Further processing of field
materials will reveal many mysteries of the unique lake and its
surroundings.
In the winter of 2008-2009. An international group of scientists
from Russia, Germany and the United States drilled the bottom of
Lake Elgygytgyn with equipment installed on the ice and studied the
bottom sediments of the lake and the rocks beneath them.
A
well drilled under a 225-meter layer of lacustrine deposits revealed
a layer of shock breccia - suevite, more than 200 meters thick.
Rocks of this type are formed only in impact craters - thus, the
meteoric origin of the lake has been confirmed.