{{Infobox body of water | name = El Junco | native_name = {{native name|es|Laguna El Junco}} | native_name_lang = | image = 250px | alt = | caption = El Junco Lagoon | image_bathymetry = | alt_bathymetry = | caption_bathymetry = | location = San Cristobal, Galapagos Islands | coords = {{coord|-0.8953|-89.4801|type:waterbody_region:EC|format=dms|display=inline,title}} | type = Volcanic crater lake | inflow = Rainfall | rivers = | outflow = None (evaporation) | catchment = | basin_countries = | agency = | designation = | length = | width = {{convert|300|m|abbr=on}}<ref name=cristo>{{cite web|url=http://www.galapagos.org/about_galapagos/about-galapagos/the-islands/san-cristobal/|title=San Cristóbal - Galapagos Conservancy}}</ref> | area = {{convert|60,000|m2|abbr=on}} | depth = {{convert|4|m|abbr=on}} | max-depth = {{convert|6|m|abbr=on}}<ref name=park>{{cite web|url=http://www.galapagospark.org/sitio.php?page=laguna_el_junco|title=Dirección del Parque Nacional Galápagos|access-date=2016-02-09|archive-url=https://web.archive.org/web/20160209184743/http://galapagospark.org/sitio.php?page=laguna_el_junco|archive-date=2016-02-09|url-status=dead}}</ref> | volume = {{convert|360,000|m3|abbr=on}}<ref name=park/> | residence_time = | salinity = | shore = {{convert|270|m|abbr=on}}<ref name=park/> | elevation = {{convert|700|m|abbr=on}} | frozen = | islands = None | sections = | trenches = | benches = | cities = <!-- Map --> |pushpin_map=Ecuador Galápagos Islands | pushpin_label_position = | pushpin_map_alt = Location of El Junco in the Galapagos Islands. | pushpin_map_caption = <!-- Below --> | website = | reference = }}

'''El Junco Lagoon''' is a lake in the highlands of San Cristóbal Island in the Galápagos Islands. Despite the name, it is a volcanic crater lake rather than a lagoon.

==History== El Junco inhabits a crater formed by the collapsed caldera of a volcano. Research has indicated the lake to have been extant since the end of the last ice age.<ref name=cristo/> The name ''El Junco'' is Spanish for sedge which is endemic to the islands.

During World War II, American forces stationed at the military base on Baltra Island utilized El Junco as a primary source of water, due to it being the closest available source of freshwater.<ref name=cristo/>

The lake is managed by the Galapagos National Park Service.

===Flooding=== Due to the lake's lack of a permanent outflow, heavy rains can cause the lake to breach its banks. Several flood incidents, often corresponding to El Nino, have been recorded. Flooding in 1978 led to an outflow being recorded at {{convert|5400|gal|abbr=on}} per hour. Similar events in 1978 and 1998 caused serious damage to the nearby Puerto Baquerizo Park.<ref name=park/>

==Ecology==

===Flora=== The name ''El Junco'' is a reference to the endemic sedge (Cyperus anderssonii) which can be found growing close to the lake. Additionally, the endangered Galapagos miconia (Miconia robinsoniana) can be found in the highlands surrounding the lake. Only two populations are known to occur in the wild, the other being in the highlands of nearby Santa Cruz island.<ref>{{cite web|url=http://www.darwinfoundation.org/datazone/checklists/598/|title=CDF Galapagos Species Checklists - Miconia robinsoniana}}</ref>

===Fauna=== Many species of birds inhabit the lake area including the endemic San Cristóbal mockingbird and white-cheeked pintail. Due to its status as an isolated source of fresh water, it is also one of the few places to witness frigatebirds preening their feathers.<ref name=park/>

<gallery> File:2022-05-21 Frigatebirds Laguna El Junco 01.JPG|frigatebirds circle above Laguna El Junco File:2022-05-21 Frigatebirds Laguna El Junco 07.JPG|frigatebird probes Laguna El Junco File:2022-05-21 Frigatebirds Laguna El Junco 10.JPG|frigatebird plunges into Laguna El Junco File:2022-05-21 Frigatebirds Laguna El Junco 22.JPG|frigatebird waters in Laguna El Junco File:2022-05-21 Frigatebirds Laguna El Junco 23.JPG|frigatebird rises from Laguna El Junco File:2022-05-21 Frigatebirds Laguna El Junco 24.JPG|frigatebird shakes the water out of its feathers File:2022-05-21 Frigatebirds Laguna El Junco 04.JPG|frigatebirds depart towards the sea </gallery>

==Research== According to a 1966 study by Dr. Paul Colinvaux, sediment at the bottom of the lagoon has a thickness of {{convert|16|m|abbr=on}}. Using radiocarbon dating, it has been found that {{convert|3|m|abbr=on}} of the top layer were deposited during the last 10,000 years, with the remaining {{convert|13|m|abbr=on}} deposited during periods of drought over the course of 38,000 years, giving a total sediment age of 48,000 years.<ref>{{cite journal|title=Climate and the Galapagos Islands|journal=Nature | volume=240|issue=5375|doi=10.1038/240017a0|pages=17–20|year=1972|last1=Colinvaux|first1=Paul A.}}</ref>

It is believed that the climate of the Galapagos went through a dry period caused by glacial advances in the Northern Hemisphere, beginning 48,000 years ago and ending 10,000 years ago.

==References== {{Reflist}} {{DEFAULTSORT:Junco }} Category:Volcanic crater lakes Category:Galápagos Islands Category:San Cristóbal Province Category:Lakes of Ecuador