Quaternary Glaciers and Climate on Cerro Chirripó, Costa Rica

2000 ◽  
Vol 54 (1) ◽  
pp. 24-37 ◽  
Author(s):  
Kenneth H. Orvis ◽  
Sally P. Horn
Keyword(s):  
Costa Rica ◽  
High Altitude ◽  
Central America ◽  
Younger Dryas ◽  
Glacial Geomorphology ◽  
Radiocarbon Dates ◽  
Tropical Glaciers ◽  
The North ◽  
Organic Sediments ◽  
Lower Limits

Glacial lake sediments and glacial geomorphology in Valle de las Morrenas, a glacial trough on the north face of Cerro Chirripó, Costa Rica, provide evidence on high-altitude Pleistocene conditions in Central America. The most recent glacier in the valley (Chirripó stage I) receded very rapidly near the end of the Younger Dryas chronozone. Radiocarbon dates on basal organic sediments from lakes beneath upper, middle, and lower limits of that glacier fall close together, and two-sigma calibrated ages overlap for the period 9700–9600 cal yr B.P. Earliest datable transition sediments from the central lake date to 12,360–11,230 cal yr B.P. Larger, older moraines, and associated trimlines, allowed reconstruction of three paleoglaciers (Chirripó stages II, III, and IV). Computer analysis of hypsometry using published tropical-glacier vertical mass balance profiles yields ELAs of 3506–3523, 3515–3537, and 3418–3509 m, respectively; Chirripó II ELA-estimate positions applied to Chirripó I yield an ELA of 3538–3546 m. We infer minimal temperature depressions of 7.4–8.0°C for the Chirripó I–IV stages. Modeling the behavior of modern tropical glaciers yields basinwide net accumulation estimates of 440–620, 550–830, and 960–1760 mm yr−1 for the Chirripó II, III, and IV stages.

scholarly journals Geographic Spread ofGnamptogenys triangularis(Hymenoptera: Formicidae: Ectatomminae)

2012 ◽  
Vol 2012 ◽  
pp. 1-4
Author(s):  
Joseph A. MacGown ◽  
James K. Wetterer
Keyword(s):  
Costa Rica ◽  
Central America ◽  
French Guiana ◽  
Buenos Aires ◽  
South American ◽  
Native Range ◽  
Southeastern Usa ◽  
The North ◽  
Geographic Spread ◽  
Major Pest

Gnamptogenys triangularis(Mayr), native to the forests of South and Central America, is a predatory ant that feeds on millipedes. In its native range, this species is known from Buenos Aires, Argentina (38.1°S) in the south to Costa Rica (10.4°N) in the north, with records from eight countries in South America (all except Chile, French Guiana, and Paraguay), and the two southernmost countries of Central America (Panama and Costa Rica). The first records ofG. triangularisoutside its native range came from Florida beginning in 1985 (six sites: 25.5°–30.4°N) and Alabama in 1996 (one site: 30.4°N). Here we present the first records ofG. triangularisfrom Mississippi, dating from 2002–2010 (five sites: 30.5°–31.2°N). Based on its South American range, it appears thatG. triangularishas the potential to spread to forests throughout much of the southeastern USA. There are no documented impacts ofG. triangularis,and it seems unlikely that this species will ever become a major pest.

scholarly journals Paleośrodowiskowe znaczenie zmian tempa i charakteru sedymentacji osadów jeziora Jelonek w Borach Tucholskich = Paleoenvironmental significance of changes in the rate and type of sedimentation in Lake Jelonek within Poland’s Tuchola Pine Forest (Bory Tucholskie)

2020 ◽  
Vol 92 (3) ◽  
pp. 409-422
Author(s):  
Mateusz Kramkowski
Keyword(s):  
Sedimentation Rate ◽  
Sediment Cores ◽  
Rapid Change ◽  
Lacustrine Sediments ◽  
Younger Dryas ◽  
Pine Forest ◽  
Radiocarbon Dates ◽  
The Holocene ◽  
The North ◽  
High Sedimentation

This paper presents the matter of the environmental reconstruction of laminated lacustrine sediments from the Younger Dryas through to the present day, in particular in respect of microlithofacial analysis and sedimentation rate. Lake Jelonek is located within the Tuchola Pine Forest of northern Poland (at 53°45’58N, 18°23’30E). It occupies a subglacial channel immediately adjacent to the Wda Valley. The lake covers 19.9 ha and has a maximum depth of 13.8 m. In 2014, overlapping sediment cores JEL14 (14.23 m) were collected from that deepest part, in order for a full sediment profile including the younger Dryas and the Holocene to be created. Most of the sediment is found to be laminated. Sedimentation rate was reconstructed for the lake, along with microlithofacial variability of different sections of the sediment. The results obtained were related to an age depth model based on 14 AMS radiocarbon dates, varve chronology and the Askja AD 1875 cryptotephra; and was correlated with pollen profiles. The Holocene sediment record of Lake Jelonek exhibits differences between low and high sedimentation rate intervals and varved and non-varved intervals. From the beginning of the Holocene through to the Subatlantic period, sedimentation proved to be a stable phenomenon. However, in the Subatlantic period, the average sedimentation rate increased to 7.7 mm per year from 2.2 mm, with maximum rates even reaching 15.3 mm/year. This period is reflected in a lack of lamination and the appearance of redeposited deposits. These changes prove particularly sensitive to local impact, with distinct alternations of low and high sedimentation rates and varved and non-varved intervals. The most probable drivers for the observed variability reflect a combination of changes of climate plus anthropogenic deforestation during periods of settlement that enhanced the sensitivity of the lake to wind stress. A summary of all analyses allowed for the identification of periods of rapid change in sedimentation, and – indirectly – for the reproduction of changes in the water level and anthropopressure in and around Lake Jelonek. Such results contribute to a better understanding of local influences on fluctuations in lake sedimentation processes characteristic for the north of Poland, but also Central Europe more widely.

Cultural Stratigraphy in Panama: A Preliminary Report on the Girón Site

1954 ◽  
Vol 19 (4) ◽  
pp. 332-343 ◽  
Author(s):  
Gordon R. Willey ◽  
Theodore L. Stoddard
Keyword(s):  
Costa Rica ◽  
Central America ◽  
Preliminary Report ◽  
Personal Communication ◽  
Canal Zone ◽  
The North ◽  
The Pacific ◽  
Internal Coherence ◽  
Atlantic Coastal ◽  
Coastal Strip

The archaeology of Panama, like that of most of lower Central America and the north Andes, has but recently emerged from a purely descriptive stage. The formulation of cultural-geographical divisions in ceramic and sculptural styles — “Cultures” as these are sometimes called — has been the most important attempt at synthesis. Lothrop (1948) envisaged four such “culture areas”: (1) Darien (Panama below the Canal Zone); (2) Coclé (the Pacific watershed in Coclé, Herrera, and Las Tablas Provinces); (3) Veraguas (Pacific highland Panama in the Province of the same name); and (4) Chiriqui (the upland country of Chiriqui Province and adjacent Costa Rica). To these Stirling and Rands (personal communication) have recently added what is probably a fifth, the Atlantic coastal strip above the Canal Zone. The internal coherence or unity of these “culture areas” is of a most general sort.

New Radiocarbon Dates for the Vedde Ash and the Saksunarvatn Ash from Western Norway

1996 ◽  
Vol 45 (2) ◽  
pp. 119-127 ◽  
Author(s):  
Hilary H. Birks ◽  
Steinar Gulliksen ◽  
Haflidi Haflidason ◽  
Jan Mangerud ◽  
Göran Possnert
Keyword(s):  
Lake Sediment ◽  
Younger Dryas ◽  
Plant Macrofossils ◽  
Early Holocene ◽  
Radiocarbon Dates ◽  
Terrestrial Plant ◽  
Radiocarbon Age ◽  
The North ◽  
Western Norway ◽  
Ams Dates

AbstractThe Vedde Ash Bed (mid-Younger Dryas) and the Saksunarvatn Ash (early Holocene) are important regional stratigraphic event markers in the North Atlantic, the Norwegian Sea, and the adjacent land area. It is thus essential to date them as precisely as possible. The occurrence of the Saksunarvatn Ash is reported for the first time from western Norway, and both tephras are dated precisely by AMS analyses of terrestrial plant material and lake sediment at Kråkenes. The Vedde Ash has been previously dated at sites in western Norway to about 10,600 yr B.P. It is obvious in the Younger Dryas sediments at Kråkenes, and its identity is confirmed geochemically. The mean of four AMS dates of samples of Salix herbacea leaves adjacent to the tephra is 10,310 ± 50 yr B.P. The Saksunarvatn Ash is not visible in the early Holocene lake sediment at Kråkenes. After removal of organic material and diatoms, the identity of the tephra particles was confirmed geochemically, and their stratigraphic concentration was estimated. From curve matching of a series of seven AMS dates of terrestrial plant macrofossils and whole sediment, the radiocarbon age of the ash is 8930–9060 yr B.P., corresponding to an age of 9930–10,010 cal yr B.P. (7980–8060 cal yr B.C.).

Investigating the roles of the Asian monsoon, the North American monsoon, and Hurricanes for efficient transport of chlorinated short-lived species to the UTLS based on in situ observations

2021 ◽  
Author(s):  
Valentin Lauther ◽  
Johannes Wintel ◽  
Emil Gerhardt ◽  
Andrea Rau ◽  
Peter Hoor ◽  
...  
Keyword(s):  
High Altitude ◽  
Central America ◽  
North American ◽  
Asian Summer Monsoon ◽  
North American Monsoon ◽  
Mixing Ratios ◽  
The North ◽  
Asian Summer ◽  
Efficient Transport

<p>Chlorinated very short-lived substances (Cl-VSLS) are not controlled by the Montreal Protocol but the recent emission increase of the Cl-VSLS CH<sub>2</sub>Cl<sub>2</sub> (Dichloromethane) and CHCl<sub>3</sub> (Chloroform) is believed to significantly increase the stratospheric chlorine loading from VSLS. Provided efficient transport of Cl-VSLS from the source region into the stratosphere further emission increases could ultimately even cause a significant delay of the predicted recovery date of the ozone layer to pre-1980 values. During the WISE (Wave-driven ISentropic Exchange) campaign in autumn 2017 excessive probing of the UTLS (upper troposphere lower stratosphere) region above Western Europe and the Atlantic Ocean was conducted from aboard the HALO (High Altitude and Long range) research aircraft. We use real-time in situ WISE measurements of CH<sub>2</sub>Cl<sub>2</sub> and CHCl<sub>3</sub> from HAGAR-V (High Altitude Gas AnalyzeR – 5 channel version) in correlation with N<sub>2</sub>O from UMAQS (University of Mainz Airborne QCL Spectrometer), as well as CLaMS (Chemical Lagrangian Model of the Stratosphere) global 3-dimensional simulations of air mass origin tracers and backward trajectories to identify the most efficient transport mechanisms for Cl-VSLS entering the LS region in northern hemispheric summer.</p><p>The WISE measurements reveal two distinct transport pathways into the UTLS region of particularly CH<sub>2</sub>Cl<sub>2</sub>-rich and CH<sub>2</sub>Cl<sub>2</sub>-poor air. CH<sub>2</sub>Cl<sub>2</sub>-rich air could be identified to be transported by the Asian summer monsoon within about 4-10 weeks from its source regions in Asia into the stratosphere above the Atlantic Ocean at around 380 K and above. CH<sub>2</sub>Cl<sub>2</sub>-poor air could be identified to be mainly uplifted to potential temperatures of about 365 K by the North American monsoon above the region of Central America with transport times of only 2-5 weeks. In addition, we could link backward trajectories of CH<sub>2</sub>Cl<sub>2</sub>-poor air in the LS region to be uplifted by the category 5 hurricane Maria in September 2017. Based on all analyzed WISE measurements, we found that almost all young (transport time < 4 months) air masses were uplifted either above Asia or above Central America, emphasizing not only the impact of the Asian summer monsoon on the stratospheric tracer distribution but also that of the North American monsoon and hurricanes.</p><p>The measurements of both CH<sub>2</sub>Cl<sub>2</sub> and CHCl<sub>3</sub> show the lowest stratospheric mixing ratios originating in the region of Central America and enhanced mixing ratios from Asia (enhancements > 100 % and > 50 %, respectively). However, the source distribution of CHCl<sub>3</sub> is much less clear than that of CH<sub>2</sub>Cl<sub>2</sub> and inconspicuous CH<sub>2</sub>Cl<sub>2</sub> measurements can also contain enhanced CHCl<sub>3</sub> mixing ratios. Nevertheless, the anthropogenic impact on CHCl<sub>3</sub> -rich air from Asia is clearly visible in the measurements and we believe it is likely that a future increase of Asian CHCl<sub>3</sub> emissions could lead to similarly large stratospheric enhancements as already observed for CH<sub>2</sub>Cl<sub>2</sub>. Consequently, this would further increase ozone depletion from stratospheric chlorine deposition of VSLS.</p>

Systematics of the Dendrophidion nuchale complex (Serpentes: Colubridae) with the description of a new species from Central America

Zootaxa ◽  
2012 ◽  
Vol 3513 (1) ◽  
pp. 1 ◽  
Author(s):  
JOHN E. CADLE ◽  
JAY M. SAVAGE
Keyword(s):  
New Species ◽  
Costa Rica ◽  
Central America ◽  
Species Group ◽  
Apical Region ◽  
The North ◽  
The Andes ◽  
The Caribbean ◽  
A New Species ◽  
Eastern Half

We review the systematics of the Dendrophidion nuchale complex in Central America and northern South America andrecognize three species. The names D. nuchale (W. Peters) and D. clarkii Dunn apply to two of the species. The third isdescribed as a new species, D. rufiterminorum. It differs from D. clarkii and D. nuchale in coloration and hemipenial char-acters but all three species of the nuchale complex are very similar in scutellation characters. Dendrophidion nuchale isdistributed in the coast ranges and adjacent foothills of northern Venezuela, and in a seemingly disjunct population in theSerranía de Perijá in western Venezuela. The name clarkii was recently applied to all populations of the nuchale complexfrom Belize and Guatemala in the north to western Colombia and Ecuador in the south. Herein, we restrict the name D.clarkii to populations in lower Middle America (Costa Rica and Panama) and west of the Andes in Colombia and Ecuador.Dendrophidion rufiterminorum is distributed in northern Central America (Belize, Guatemala, northern Honduras) fol-lowed by a broad disjunction without records of the species throughout most of Honduras and Nicaragua; thereafter, a fewspecimens and photographs document the presence of D. rufiterminorum on the Caribbean versant of southern Nicaraguaand Costa Rica, and uplands of northwestern Costa Rica (Pacific versant). Two localities of sympatry between D. rufiter-minorum and D. clarkii are known in Costa Rica (one on the Atlantic versant, the other on Pacific versant). Nonetheless,there is sparse documentation of either species in Costa Rica. The populations referred to D. clarkii in southwestern CostaRica, the eastern half of Panama, and western Colombia and Ecuador need further study. Hemipenes of species of thenuchale complex are described. All three species have a pair of enormously enlarged sulcate spines and a regular lineararray of enlarged spines (spinose annulus) encircling the base of the apical region. These characters are also shared with D. dendrophis sensu lato but not other members of the dendrophis species group.

Rapid Ice Margin Fluctuations during the Younger Dryas in the Tropical Andes

2000 ◽  
Vol 54 (3) ◽  
pp. 328-338 ◽  
Author(s):  
Donald T. Rodbell ◽  
Geoffrey O. Seltzer
Keyword(s):  
Younger Dryas ◽  
Late Glacial ◽  
Tropical Andes ◽  
Radiocarbon Dates ◽  
Peruvian Andes ◽  
Southern Peru ◽  
Ice Cap ◽  
The North ◽  
Glacier Advance ◽  
Lake Deposits

Radiocarbon dated lacustrine sequences in Perú show that the chronology of glaciation during the late glacial in the tropical Andes was significantly out-of-phase with the record of climate change in the North Atlantic region. Fluvial incision of glacial-lake deposits in the Cordillera Blanca, central Perú, has exposed a glacial outwash gravel; radiocarbon dates from peat stratigraphically bounding the gravel imply that a glacier advance culminated between ∼11,280 and 10,990 14C yr B.P.; rapid ice recession followed. Similarly, in southern Perú, ice readvanced between ∼11,500 and 10,900 14C yr B.P. as shown by a basal radiocarbon date of ∼10,870 14C yr B.P. from a lake within 1 km of the Quelccaya Ice Cap. By 10,900 14C yr B.P. the ice front had retreated to nearly within its modern limits. Thus, glaciers in central and southern Perú advanced and retreated in near lockstep with one another. The Younger Dryas in the Peruvian Andes was apparently marked by retreating ice fronts in spite of the cool conditions that are inferred from the ∂18O record of Sajama ice. This retreat was apparently driven by reduced precipitation, which is consistent with interpretations of other paleoclimatic indicators from the region and which may have been a nonlinear response to steadily decreasing summer insolation.

Shallow-focus seismicity, composite focal mechanism, and tectonics of the Valle Central of Costa Rica

1982 ◽  
Vol 72 (5) ◽  
pp. 1611-1626
Author(s):  
Walter Montero P. ◽  
James W. Dewey
Keyword(s):  
Costa Rica ◽  
Central America ◽  
Plate Boundary ◽  
Strike Slip ◽  
Nodal Plane ◽  
Intraplate Earthquakes ◽  
The North ◽  
Source Regions ◽  
Volcanic Chain ◽  
Shallow Focus

abstract A network of seismographs operating in the Valle Central of Costa Rica has recorded many small earthquakes near the cities of Cartago and San Jose. This seismicity is similar in many ways to the shallow-focus intraplate seismicity of Central America to the north. The earthquakes occur within tens of kilometers of Quaternary volcanic centers at shallow focal depths. The earthquakes occur predominantly on strike-slip faults, with the nodal plane that would correspond to a left-lateral fault striking approximately east-northeast and the nodal plane that would correspond to a right-lateral fault striking approximately north-northwest. The shocks have a tendency to occur in seismic swarms. The region of highest seismicity in our study was located southwest of Cartago, about 10 km from the meizoseismal zones of destructive earthquakes of 1841 and 1910. In detail, the recently recorded small earthquakes seem to have occurred on different faults or fault segments than the 1910 earthquakes. The tendency for shallow-focus intraplate earthquakes to occur within kilometers of earthquakes that occurred several decades earlier has been noted elsewhere in Central America. The occurrence of shocks on distinct faults within the overall region of high activity appears similar to the occurrence of earthquakes on different fault strands in Managua, Nicaragua. We discuss the Valle Central seismicity in light of hypotheses proposed for the shocks farther north in Central America. Our data can be interpreted in terms of the hypothesis that shallow-focus intraplate earthquakes in Central America concentrate on zones of strike-slip faults that pass through offsets of the volcanic chain. Our data can also be interpreted in terms of the hypothesis that the earthquakes occur as the response of minor faults to high regional stresses throughout the region surrounding the volcanic chain. Both hypotheses leave some characteristics of the seismicity unexplained, although these characteristics are not crucial evidence against the hypotheses. A third hypothesis, that the Valle Central source regions are different than intraplate source regions northward in Central America and are occurring in a developing transform plate boundary between the Caribbean and Nazca plates, is plausible on the basis of the regional plate tectonic environment, but it is not strongly supported by the local geology of the Valle Central or by the characteristics of seismicity.

The Tronadora Complex: Early Formative Ceramics in Northwestern Costa Rica

1994 ◽  
Vol 5 (1) ◽  
pp. 3-30 ◽  
Author(s):  
John W. Hoopes
Keyword(s):  
Costa Rica ◽  
Central America ◽  
Formative Period ◽  
Central American ◽  
Radiocarbon Dates ◽  
Southern Central ◽  
Tephra Stratigraphy ◽  
Middle Formative ◽  
High Degree ◽  
Early Formative

The correlation of archaeological features with tephra stratigraphy and radiocarbon dates in the volcanic cordillera of northwestern Costa Rica has provided evidence for an Early to Middle Formative ceramic complex dating to at least 2000 B.C. Tronadora ceramics have been found in association with evidence for early horticulture and sedentism. Stylistic comparisons with other early pottery from Central America have helped with the refinement of our chronology for the earliest sedentary societies in Costa Rica and Nicaragua. Differences between Tronadora pottery and the earliest complexes of Mesoamerica and southern Central America indicate a high degree of regionalization in ceramic styles during the Early Formative period. Similarities also indicate, however, the common participation of northwestern Costa Rica and southern Mesoamerica in broad interaction networks at this time. Tronadora pottery does not represent an incipient technology or the result of a diffusion of ceramic production from Mesoamerica or northwestern South America. Instead, it implies the existence of an earlier and still-undefined period of technological experimentation in the Central American isthmus.

Central America's tourism development gap set to grow

2015 ◽  
Keyword(s):  
Costa Rica ◽  
Central America ◽  
Developed Countries ◽  
Eastern Coast ◽  
Economic Downturn ◽  
Medium Term ◽  
Content Type ◽  
The North ◽  
Southern Central ◽  
Development Gap

Subject Southern Central America's preparations to invest more in tourism. Significance The countries of Central America are experiencing mixed fortunes in attracting international tourism, with Costa Rica and Panama benefiting from well-established and dynamic tourist sectors, while the less developed countries to the north of the isthmus -- El Salvador, Honduras, Guatemala and Nicaragua -- trail behind. The countries look set to continue diverging over the medium term, as Costa Rica and Panama diversify their tourist sectors and develop new tourism infrastructure. Impacts With the region's tourism industries heavily reliant on North America, any US economic downturn would be very damaging. Costa Rica's efforts to open up its eastern coast could provide a major new regional hub for resort tourism. A stronger dollar could encourage US tourism in countries, such as Guatemala and Nicaragua, whose currencies are not pegged to the dollar.

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