Essay, Research Paper: Remote Sensing Research In Maya Area

Introduction
During the second session of the summer 2000 WBRCP we gathered data for Remote Sensing research. Our objective is to locate cave sites and determine the usefulness of various remote sensing platforms for this purpose. Similar research has proven successful for locating surface sites in the Maya area, but this technology has not yet been applied for cave location. Finding cave sites is particularly important to Maya archaeology because they often contain archaeological material, much of which is undisturbed and in primary context. However, due to the prevalence of looting in the Maya area it is important for archaeologists to find these sites before they are disturbed. Simply re-locating known cave sites in the jungle can be a monumental task, and finding new, undisturbed caves can be nearly impossible deep in the rainforest. We believe that utilizing this technology will aid us in the search for caves in the jungles of Belize.
History of Remote Sensing Research in Maya area
The use of remote sensing in archaeological research in the Maya area began relatively recently. In the late 1960’s Alfred Siemens’ interest in identifying agricultural features within the jungle landscape prompted the initial use of aerial photography (Siemens, 1982). Using a combination of photography and infrared photography Siemens and Puleston (1972) identified ridged fields and canals in the floodplains of southern Mexico. Following up on this research Richard Adams employed synthetic aperture radar (SAR) and side-looking aperture radar (SLAR) in an extensive mapping endeavor in the late 1970’s (Adams, 1980). Adams detected major architecture and sacbes (roads) and lattice patterns in wetlands that he defined as man-made agricultural features. Adams found these features everywhere and he used this to argue that wetland agriculture was the cornerstone of Maya subsistence practices.
Also in the late 1970’s Payson Sheets used ground penetrating radar (GPR), seismic refraction, and resistivity at the site of El Ceren in El Salvador (Sheets, 1979). The Ilopango volcano erupted in 300 AD, covering the site and freezing it in time. Sheets was able to detect ancient Maya structures beneath lava fields using these techniques.
In 1989 Kevin Pope and Bruce Dahlin reexamined the area where Adams had previously worked (Pope and Dahlin, 1989). They employed the use of Landsat TM imagery as well as Seasat radar imagery in their study, and they produced different results than Adams. They could not reproduce the detection of Adams’ lattice patterns, and concluded that wetland agriculture was not a primary system employed by the ancient Maya.
In the 1990’s Patrick Culbert and Thomas Sever used Landsat TM imagery to locate ancient Maya causeways and pyramids (Sever, 1998). Much of their effort has been focused on the identification of bajos, or wetlands, in northern Guatemala. Again the questions being asked are regarding agricultural practices and subsistence. Sever and Culbert’s work marks the most recent and extensive use of satellite data in Maya archaeology.
Image Preparation
Prior to arriving in Belize we prepared a LANDSAT 5 image of Belize, path 19 row 48, for use in the field. This preparation consisted of obtaining 1:50,000 scale Universal Transverse Mercator maps and georegistering subscenes of the satellite image that correspond with the study area. Dr. Rick Wilk and Dr. Anne Pyburn of Indiana University provided the LANDSAT 5 image. Dr. Eduardo Brondizio, Dr. Emilio Moran made available to us facilities at the Anthropological Center for Training (ACT), Indiana University. This image/map was used as a field reference.
Data Collection Protocol
We collected several forms of data over the summer at cave sites that are already known, many of which are currently under investigation by the WBRCP. The remote sensing platforms record reflectance of electromagnetic waves from the earth’s surface. We collected vegetation and temperature data at the entrances of caves that we intend to use to assemble a cave “signature” or signatures in the multispectral and thermal bands of the satellite platforms. Also, we used a Garmin GPS III to determine locations of the research sites.
We used three HOBO H8 family temperature loggers to record thermal information around the cave entrances at two-minute intervals. One was placed just outside of the entrance to the cave, the second on the ground atop the cave passage (where possible), and the third logger was placed 100 meters from the cave entrance as a control. GPS points were taken at each logger position. With this placement of the loggers we intended to record thermal changes in the environment due to cooler temperatures of the air and water that come from the relatively static temperatures of the subterranean passages. We also noted site specific factors affecting the thermal environment. Leon Benrimon then calculated the greatest temperature difference (GTD) between any two of the three loggers at each site.
Vegetation, especially those species which make up the high jungle canopy, is the primary factor that affects the reflectance of the electro-magnetic information in the visible range that is recorded by the satellite. At the cave sites we performed a basic classification of the environment, e.g. broad leaf ridge, pine ridge, milpa, et cetera. We also recorded the dominant canopy species. Finally we took black and white photographs from the ground of the canopy with a fisheye lens. The 180-degree range of the fisheye lens provides photographs that can be used to determine the percentage of canopy coverage.
The Cave Sites
We visited sites in several areas of central western Belize including the Macal River Valley, the Roaring Creek Valley, the Barton Creek Valley, and the Caves Branch area as well as an exciting new cave south of San Antonio. This broad survey yielded data on a variety of cave types and contexts as well as a broad geographical distribution of caves. We also created a basic typology of cave entrance morphology.
A : Large Horizontal Entrance – Entrance greater than 3 m in diameter
B : Sinkhole Entrance
C : Small Horizontal Entrance - Entrance less than 3 m in diameter
D : Rock Shelter, no significant dark component
To these types the presence of water may be appended when appropriate.
-w : contains water
-wp : contains water periodically
Macal River Valley
Cave: Contreras Cave Sinkhole
Crew: Cameron Griffith, Rusty Peterson, William Pleytez, Rock Ortega
(Assistance and consultation given by the Menanha Regional Survey, Sam Connell,
Principal Investigator)
Cave Type: B
GTD: 6.3 degrees
We hiked into the Macal Valley in search of the field camp of the Minanha Regional Survey (MRS) archaeological project. After a two-hour slog over a muddy road though the jungle we met up with archaeologists Sam Connell and Ted Neff, who kindly directed us to a large sinkhole near a small group of surface structures that they were excavating. The MRS research area and the sinkhole are located on the northern end of the Vaca Plateau. The sinkhole was named Contreras Sinkhole after landowner Enrique Contreras.
Contreras Sinkhole is particularly interesting for the remote-sensing project, because it is located in the middle of a milpa. Because of clearing for the planting season, there is essentially no forest canopy near the feature. Only a few cohune palms grow amid the cornfield, which in previous years has also been planted with beans. Thus the vegetation composition in the area is quite basic, and there is no canopy to interfere with any temperature differential created by the air emanating from the sinkhole. Also of interest is an old mahogany logging road that passed next to the sinkhole, it was in use until 12 to 15 years ago.
The team rappelled 22 meters (72 feet) to the bottom of the sinkhole and discovered that it is merely a cylinder with no branching passages or tunnels. The lack of a significant horizontal subterranean component may be the reason why there is little difference in the temperature of the air coming from the sinkhole versus the surface environment around the entrance.
A part of the vegetation signature hypothesis is that animal activity at cave entrances will affect the ecology of entrance area significantly enough to be detected with the satellite images it was interesting to see major swallow activity as well as bat activity in the sinkhole entrance. The corn growing n the milpa was about 30cm tall during our visit on the 17th of July. In past years the milpa has been planted to rice and beans. Aside from the managed vegetation species the dominant vegetation is Cohune Palm which is typical of an area in milpa as they resist the clearing process. Several different pants were growing from the sinkhole entrance including Chia, Wild Grape, Trumpet Tree, Heart Plum, Give and Take Palm, Papaya, a dead Bits Wood (about 10m tall) and a dead Basin Cedar (about 10m tall).

Cave: Crystal Pit Sinkhole
Crew: Cameron Griffith, Rusty Peterson, Bruce Minkin, William Pleytez
Cave Type: B
GTD: 13.2 degrees
William Pleytez, who grew up in the Macal Valley, led the team to another sinkhole. William informed us that the sinkhole had been dubbed the "Crystal Pit" and that it appeared to have subterranean passageways. The area around the entrance was burned by a fire that in late April-early May of this year raged uncontrolled over a large area in the Macal Valley. As a result of the fire, there is only meager vegetation below the broken canopy. Considering that this cave has a substantial dark area this site creates a situation that will be interesting to observe in the thermal bands because of the light vegetation cover.
The Crystal Pit had not yet been visited by the WBRCP, so a brief reconnaissance of the cave was necessary. The team rappelled 28 meters (91 1/2 feet) to the bottom of the sinkhole, and, as we suspected, there are a number of subterranean rooms and passages in the cave. Directly under the sinkhole there is architecture in the form of terraces or steps that lead down into a large room. We soon discovered that the Crystal Pit was aptly named--the chambers within are filled with beautiful, sparkling aragonite formations that glow bright orange when you backlight them with your flashlight. The Crystal Pit contains human skeletal remains, potsherds, burned wood, and an abundance of charcoal and ash. A sketch map was made and the artifacts tabulated. The WBRCP may investigate this cave further in future field seasons.
William pointed out several species around the entrance of the Crystal Pit that are favored by bats such as Heart Plum, Fiddlewood, Wild Cherries, Black Chechem, Trumpet Trees, and Rumon (Breadnut). Wild cherries were most abundant followed by Heart Plum, Fiddlewood, and Trumpet Trees. Other species near the entrance include Basin Cedar, Give and Take Palm, Bayleaf Palm Cabbage Bark, Morning Glory, and Trumpet Tree.
The GTD for this sink hole is one of the highest recorded this summer. This is exciting, but it should be noted that the temperature readings were taken on a warm mostly sunny day and that due to the recent burning episode the loggers (especially those away from the sinkhole entrance) were subject to direct sun.
Cave: Actun Chapat
Crew: Cameron Griffith, Rusty Peterson, Bruce Minkin
Cave Type: B/A-wp
GTD: 3.7 degrees
Since the WBRCP had already conducted research in Actun Chapat in the 1999 season and in June of 2000, our objective was only to conduct the remote-sensing research. Actun Chapat translates as "Cave of the Centipede." The cave has two entrances, a sinkhole entrance and a horizontal entrance. On the first day we collected the remote-sensing data at the sinkhole entrance. While smoking a cigarette on the downhill edge of the sinkhole, we noticed the smoke being pulled into the hole. This is a phenomenon that a fellow project member, Mike Miro, had mentioned to the group as a feature specific to certain caves. While we were watching the smoke travel down into the sinkhole entrance the airflow suddenly reversed and the cave blew air out with strength comparable to the inflow a minute before. After only seven minutes of blowing the cave returned to sucking air. This sort of phenomenon certainly affects the thermal environment of a cave entrance. As a result of this experience our protocol includes recording the airflow at cave entrances as an element of the remote-sensing data.
The vegetation in the vicinity of entrance two mostly consisted of Cohune but as well Give and Take Palm. Entrance one however was dominated by Pacaya, Chechem, Wild Tamarin, Gumbo Limbo, and Give and Take Palm as well as an unidentified plant that infested the arroyo known only as the 110volts plant (William’s name). Animal activity includes swallows and bats lizards and frogs.
The GTD for this cave is relatively small. Although cold air is emitted by this large cave entrance it sinks down an arroyo to a low point where the arroyo meets a stream bed. Temperature loggers 2 and 3 were located in the arroyo and streambed respectively. Thus it is not surprising that the difference is so small.
Cave: Son of Chapat
Crew: Cameron Griffith, Rusty Peterson, Bruce Minkin, William Pleytez
Cave Type: A-wp
GTD: 4.4 degrees
The one known entrance of Son of Chapat is similar in morphology to the horizontal entrance of Actun Chapat. This cave also floods, and when it does the water feeds into the same arroyo as the water from Actun Chapat, but a few kilometers up the arroyo. William Pleytez lives only a few kilometers away from these caves and over the years he has witnessed many flooding episodes in the area. He reported that water literally shoots from the entrance of Son of Chapat into its streambed. On our way to Chapat and Son of Chapat we walk through this arroyo. It is obvious from the large piles of brush and the absence of large trees that this arroyo carries a substantial volume of water during the flooding episodes that occur quite frequently during the wet season. If we are able to pinpoint the dates of flooding in Son of Chapat we may be able to further define a spectral signature for caves that emit water either periodically or with regularity.
The vegetation of the broadleaf forest surrounding the entrance of Son of Chapat consists mainly of Cohune Palm, Give and Take Palm, and Pacaya palm.
The thermal situation at Son of Chapat is nearly identical to that at Actun Chapat. But here one temperature logger was placed away from the entrance and up hill from the arroyo and streambed, but this did not produce a much greater GTD than that recorded at Actun Chapat.
Cave: Actun Halal
Crew: Cameron Griffith, Rusty Peterson, Bruce Minkin, William Pleytez, Matt Kalch,
Kimo Jolly, Henry Badilla, Anh-Thu Cunnion, Lauren Tobias,
Cave Type: A
GTD: 2.8 degrees
Actun Halal is located between Actun Chapat and Son of Chapat, only 100 meters (327 feet) from the entrance of Son of Chapat. It is morphologically quite different than these caves, however. It has two large horizontal entrances that are only 40 meters (131 feet) apart as well as a minor dark-zone component. This cave does not flood and does not have a streambed like the other two nearby caves. This close proximity to the other caves coupled with the morphological difference should provide an interesting comparison when we look at this area with the satellite images. We monitored temperature at Actun Halal and Son of Chapat concurrently. This should also make for an interesting comparison when we analyze these data.
The vegetation of the broadleaf forest surrounding the entrance of Actun Halal consists mainly of Cohune Palm, Give and Take Palm, and Pacaya Palm.
Actun Halal has a very small dark component. Really it is like a rock shelter with two large entrances. Thus, it is not particularly surprising that the GTD is so small.
Cave: Actun Che Chem Ha
Crew: Cameron Griffith, Rusty Peterson
Cave Type: C
GTD: 6.7 degrees
Actun Che Chem Ha (Poisonwood Water Cave) was investigated by the WBRCP in the 1998 and 1999 field seasons. William Pleytez's family members are the stewards of the cave. William's mother and brother, Lea Castellanos and Gonzalo Pleytez, lead tours through Che Chem Ha. The cave has a small horizontal entrance (less than one meter in diameter) half way up a large limestone karst hill. The size of the entrance makes it unlikely that it will produce a significant thermal differential. This cave exhibits animal activity that, if our hypothesis is correct, will affect the vegetation in the cave entrance microenvironment. According to William this hillside was also subject to the same burning episode in May of 2000 that claimed the understory around Crystal Pit sinkhole. This may provide another interesting comparison.
The broadleaf forest with an understory recently cleared by burning consisted mainly of Heart Palm, Basin Cedar, and Chechem, but also of Fiddle Wood, Give and Take, Bay Leaf, Cabbage Bark, Morning Glory, Trumpet Tree, and Wild Cherry. Animal activity includes bat, snake, gibnut, and insects.
The GTD at Actun Che Chem Hais greater than expected considering the temperatures were recorded on a particularly cool day, so the ambient jungle temperature was cool. Also the entrance to this cave is fairly small.
Cave: Serpent Cave
Crew: Cameron Griffith, Rusty Peterson, William Pleytez, Kimo Jolly, Henry Badilla,
Molly Sandgren, Matt Kalch
Cave Type: A
GTD: 4.2 degrees
Serpent Cave has a large horizontal entrance that quickly closes down to a tube less than a meter in diameter. Although it had been extensively looted, this cave had not been archaeologically investigated. There was dripwater activity in the entrance of the cave at the time of our visit which created a small pool. This hydrological activity may only be seasonal in Serpent Cave. Comparisons of satellite images of Serpent Cave during dry conditions versus wet conditions could help us locate caves with similar hydrology.
The vegetation of the broadleaf forest surrounding Serpent Cave consisted mainly of Give and Take Palm, Rumon (Breadnut), and White Chechem, but also of Bitterwood, Santa Maria, Bayleaf Palm, Cohune, Grape vines, Honey Sucker (Duende vine), small specimen of Sapodillo, Bully Hop, Wild Olive (Negrito), Fiddlewood. Several species of ground cover were also identified here including Pheasant Tail, Morning Glory, Wild Papaya, Chia, Frangipani, Gumbo Limbo, and Amapola. The only indication of animal activity was evidence of Gibnut activity.
Cave: Stela Cave
Crew: Cameron Griffith, Rusty Peterson, William Pleytez, Kimo Jolly, Henry Badilla,
Molly Sandgren, Matt Kalch
Cave Type: A
GTD: 4.2 degrees
This cave, like Serpent Cave, had not been explored by archaeologists prior to our investigation. After recording the remote-sensing data outside the large horizontal entrance, we explored and mapped the cave. Although this cave had been looted, the archaeological remains we encountered were very impressive. Stelae Cave boasts a monument 2.9 meters (9 1/2 feet) long, pottery caches, and architecture. In this cave the ancient Maya were modifying the stalagmitic formations to create eye-holes. It is possible that they were then backlit by torches to provide an eerie effect, similar to that of a modern Jack-o'-Lantern. The cave also has two negative handprints that were produced in the same fashion as those in Actun Uayazba Kab.
The vegetation of the broadleaf forest surrounding the entrance to Stela Cave consists mainly of Give and Take Palm, Cohune Palm, and Heart Plum, but also, White Chechem, Allspice, Copal, Fiddlewood, Mohowood, Trumpet Tree, Grape Vine, Wild Cinnamon, Prickly Yellow, Cow Hoof Vine, Breadnut, Bull Horn Ecacia, and Wild Yam.
Animal activity consists of swallow, rat, termite, and bat, the ground around the entrance to Stela cave was covered with heart plum nuts as well as wild almond, and fiddlewood seeds, all of these are food for bats according to William.
Roaring Creek Valley
We sampled more caves in the Macal Valley than any other region for the remote sensing project, but we did broaden the geographical range of the sampling by working in the Roaring Creek Valley, we recorded data from six different cave entrances in this region.
Cave: Actun Tunichil Muknal
Crew: Cameron Griffith, Rusty Peterson, Megan Lundy
Cave Type: A-w
GTD: 6.3 degrees
The first cave we visited in the valley was one of the more important caves in the WBRCP research design. Actun Tunichil Muknal is a very impressive cave, not only in terms of the beautiful rock formations, but also because of the archaeological assemblage that was excavated by the WBRCP in 1997 and 1998. This cave is located just 50 meters from the camp. Tunichil Muknal has a large vertical entrance that is located at the base of a karst rock face. It is the source for the Muknal stream, whose cold waters flow outside the cave for about 130 meters before meeting up with the significantly warmer Roaring Creek. We believe that such a temperature difference will likely show up in the thermal band of certain satellite images. In a situation such as this, it is also likely that the species growing in and around the stream will be apparent in the visible bands of the satellite image(s). If these environmental conditions show up on the images, we can use the information from Tunichil Muknal to locate similar streams in Belize. Where the streams disappear into landforms may be where cave entrances are located.
The vegetation of the broadleaf forest surrounding the entrance of Acutn Tunichil Muknal consists mainly of Cohune Palm, Rumon (Breadnut), and Chicoloro, as well as Red Cedar, Strangling Fig, Give and Take Palm, and Gingueo Vine. Animal activity includes snake, bat, swallow, and insects.
Comparatively this cave has a significant GTD between the entrance and surrounding forest. This is likely attributed to the large amount of cold water that flows from this cave.
Cave: Actun Uayazba Kab
Crew: Cameron Griffith, Rusty Peterson, Megan Lundy, Leon Benrimon
Cave Type: A
GTD: 6 degrees
Actun Uayazba Kab is a rough translation for "Handprint Cave." It is named so because several negative handprints were found on the cave. Uayazba Kab is dry and is located halfway up a karst rock face. It has two large entrances that are similar in height and width to the entrances of Actun Halal. Uayazba is a dry cave, but it becomes active in times of extremely heavy rainfall in the area. This, coupled with the modest dark zone component, results in ambient temperatures near the entrance of the cave that are significantly cooler than the surrounding jungle. This may be detectable in the thermal bands of certain satellites.
The vegetation of the broadleaf forest surrounding the entrance of Actun Uayzaba Kab consists mainly of Rumon, Cohune Palm, and Give and Take Palm, as well as Duende Vine, and Cockspur. Animal activity includes bat, gibnut, and insects.
Cave: Actun Nak Beh
Crew: Cameron Griffith, Rusty Peterson, Sherry Gibbs
Cave Type: C/D
GTD: 5.1
Actun Nak Beh translates to "Cave at the End of the Road." It is named so because there is a sacbe, which means "white road," that leads from the cave entrance to the surface site Cahal Uitz Na. Actun Nak Beh has a horizontal entrance like a rock-shelter. It is at the base of a limestone karst hill and will flood periodically. During the month of July, Nak Beh flooded badly enough to fill one of the excavation units in the entrance. This periodic flooding, along with the pinpointed dates of the hydrologic activity, may help us locate caves with similar hydrologic properties.
The vegetation surrounding the entrance of Actun Nak Beh consists mainly of Rumon, Trumpet Tree, and Morning Glory (ground cover). Gibnut activity is also noted in this cave.
Cave: Actun Yaxteel Ahau
Crew: Cameron Griffith, Rusty Peterson
Cave Type: A-w
GTD: 7 degrees
Yaxteel Ahau translates to "Cave of the Ceiba Tree Lord." Yaxteel has a large horizontal entrance and a number of sinkhole entrances. The Yaxteel stream flows from this entrance and its cold waters flow for about 300 meters before it, like the Muknal stream, meets with the much warmer waters of the Roaring Creek. With regard to the remote-sensing signatures, Actun Yaxteel Ahau and Actun Tunichil Muknal are very similar. It will be interesting to see if a pattern for caves with streams emerges from caves such as these.
The vegetation surrounding the entrance of Actun Yaxteel Ahau consists mainly of Rumon, Cohune Palm, and Give and Take Palm. The area surrounding the sinkhole entrance (where temperature logger 3 was placed) was infested with Pacaya Palm. Snake activity was observed, that is Cameron had a close encounter with a fer de lance.
Cave: Laberinto de las Tarantulas
Crew: Cameron Griffith, Rusty Peterson
Cave Type: C
GTD: 19.2 degrees
Laberinto de las Tarantulas translates to "Labyrinth of the Tarantulas." Tarantula Cave is located near the base of a karst limestone hill. It has two small horizontal entrances that blow cool air. Because of the diminutive size of these entrances the external temperature differential is not as great as that from the caves with larger entrances. This cave does have animal activity i.e. bats, gibnuts, snakes, insects, and spiders (especially tarantulas). One of the most interesting aspects of Tarantula Cave is a large slate stelae monument within a small chamber. This monument is quite similar in size to those found in the stelae chamber of Actun Tunichil Muknal.
The vegetation surrounding the entrance to Laberinto de las Tarantulas consists mainly of Trumpet Tree, Red Head, and Cohune Palm, as well as, Pakaya Palm and Wild Yam.
The GTD for this cave is surprisingly high, especially considering that the entrance to this cave is so small. The extreme temperature difference is likely attributable in part to the warm sunny conditions during the logging time and because temperature logger1 was placed in direct sunlight.
Cave: Humming Bird Cave
Crew: Cameron Griffith, Rusty Peterson
Cave Type: A-w
GTD: 13.2 degrees
Hummingbird Cave has not yet been explored by the WBRCP. As we did not have the minimum number of people to safely explore the cave (three people), we did not conduct reconnaissance within the cave. However, we were able to collect data for the remote-sensing project outside the entrance. Hummingbird Cave is at the base of a hill, and like Yaxteel and Tunichil it has a stream flowing out of it that eventually merges with the Roaring Creek. Hummingbird Cave should strengthen the data base for a cave signature, either thermal- or vegetation-specific, for caves with constant water flow.
This cave has a large entrance from which a large amount of water flows. This and the fact the there was full sun and warm temperatures during the logging help explain the large GTD.
Barton Creek, Caves Brach, and Actun Ka’am
In addition to the caves in the Macal Valley and the Roaring Creek Valley we visited several other caves in western Belize.
Cave: Barton Creek Cave
Crew: Cameron Griffith, Rusty Peterson, Rock Ortega, Bernard Neal
Cave Type: A-w
GTD:
Barton Creek Cave was excavated this season by the WBRCP. This cave has a large horizontal entrance and like three of the caves in the Roaring Creek Valley it produces a cold stream year round that mingles with Barton Creek in a large pool just outside the entrance to the cave.
Thanks to Bernard Neal’s help with plant identification one the most extensive vegetation descriptions we collected was from Barton Creek Cave. He also identified many species that are found along the stream that runs from the cave. The most prominent species is White Cechem followed by Cow Itch and Santa Maria. Other species near the cave entrance are Turtle Bone, Oronwood, Marasorillo, Luen, Wild Desota, Ceiba, Trumpet Tree, Cha Oncha, Wild Burbre. Species that he noted near the cave and along the stream include Redwood, Catchatoone, Whistle Tree, Amapola, Rumon (Breadnut), Quam Wood, Grandy Betty, Bitterwood, Juwker Wood, Tricky Yaca, Bohowe, and Grapevine.
Animals active in Barton Creek Cave include gibnut, bat, swallow, snakes ,water possum, and spiders.
Cave: Tiger Snail Cave
Crew: Cameron Griffith, Rusty Peterson, Mike Miro, Vanessa Miro, Kimo
Jolly, Henry Badilla, Matt Kalch, Gina Zavala, Sonia Guajardo
Cave Type: A-w
GTD:
We came across Tiger Snail Cave by accident during a cave reconnaissance trip in the Barton Creek Valley on the 10th of August. We went through the reconnaissance procedures and remote sensing protocol. This cave has a large horizontal entrance and produces a cold stream.
The vegetation around the entrance to Tiger snail cave consists mainly of Cohune Palm, Bay Cedar, and an unidentified vine. Other species present include Pakaya Palm, Melistoma, Prickley Bamboo, Cassia, Wild Ginger (Awapani), Cocoyol, Hog Plum. Also of note is a large area on level ground due west of the entrance. This large space looks to have been under intensive management for some time. Much of it consists of mowed grass but there are also many citrus trees, banana trees and coconut palm.
Cave: Caves Branch Rock Shelter
Crew: Cameron Griffith, Rusty Peterson, Matt Kalch
Cave Type: D
GTD:
This rock shelter will likely be negative data for the remote sensing project. It has no significant dark component so there is really no detectable temperature difference here. There is animal activity though so there is still a possibility of this cave showing up in the visible bands.
Time was limited at the Caves Branch Rock Shelter, but the vegetation appeared to be dominated by Cohune Palm, Give and Take Palm, as well as Rumon. The under story had been cleared for during excavations years before so the ground was covered in various small vines. Bat, snake, and gibnut are all known to inhabit the area.
Cave: Lost World Cave
Crew: Cameron Griffith, Rusty Peterson, Mario Perez, Matt Kalch
Cave Type: B
GTD:
Ian Anderson informed us of the Lost world Cave which is a sinkhole that is on top of a ridge in the Caves Branch area. We opted to enter the hole through a crevasse entrance that consists of about 20 meters of passage filled with archaeological remains. The surface opening of the sinkhole is greater than 20 meters in diameter so the vegetation in the base of the hole gets plenty of light. So information was gathered within and around the sinkhole. On the way to the cave our guide, Mario, gave a very detailed account of the vegetation including scientific names which will be very helpful for us in our research.
The vegetation within this large sinkhole consists mostly of one large tree, an Anona Reticula. Also dominant within the sinkhole were Pacaya Palm, and Give and Take Palm.
Cave: Actun Ka’am
Crew: Cameron Griffith, Rusty Peterson, Sherrie Gibbs, Matt Kalch, Maria
Garcia, Juana Garcia, Patrick Warrior
Cave Type: A
GTD:
On the 15th of August two of the Garcia sisters, Maria and Juana, showed us the way through a very overgrown path south of San Antonio to Actun Ka’am. This cave has three large horizontal entrances on the top of a ridge. The fact that the entrances are on a hill top will make for an interesting comparison with many of the other caves whose entrances are in valleys.
The vegetation around the hilltop entrances to this cave consists mainly of Hog Plum, Cohune Palm, and Give and Take Palm. Also observed were Bay leaf Palm, Tedwood, Fiddle wood, Water Vine, Wild Yam (Cocolmeca), White Chechem, Wild Cherry, Copal Bohung, White Malady, Snake Plant, Sacuche, Cockspur, Spodillo, Santa Maria, Wild Fig, Basket Tietie, Wild Mame, Cedar, and Trumpet tree.
Discussion
Conclusions regarding the feasibility of locating caves using remote sensing are not yet clear. In order to make such conclusions we must process the Landsat 5 image using the data collected. Acquisition and processing of higher resolution platforms would beneficial as well. Despite the work yet to be done we developed many impressions while collecting the data.
We hypothesized that troglodytic fauna may impact the cave entrance microenvironment enough to render it detectable from remote sensing platforms. While in the field local research assistant William Pleytez supported this idea. He informed us of several plant species he commonly associates with cave entrances, Heart Plum, Fiddle Wood, Chechem, Trumpet Tree, and Rumon (Breadnut). These are species favored by bats for food; they are also all potential canopy species in a given area. This kind of support, from someone intimately familiar with the forests of the Macal Valley was very exciting. We did notice that these species are often in close proximity to cave entrances; unfortunately they are also generally common to the forests in the study area. Thus, from field observations it is not clear that these or any other canopy species are present in any greater frequency near cave entrances than in other areas of the forest.
We also noted a strong association between Pacaya Palm and sinkholes, but again it is not yet determined what significance, if any, this has on remotely sensed imagery.
Yet another phenomenon observed by William is the association of certain species of vegetation with water. Santa Maria, Figs, Bullet Tree, Mahogany, Wild Tamarin, and Cedars frequently grow near water. This may be significant in the location of wet caves. If these species are present in great enough frequency near water they may be detectable in remotely sensed imagery. If this is indeed the case it would create a trail in the image that leads to the source of this water, if that source is a cave we will have located it. But again it is not determined that such a vegetation assemblage exists and is detectable with remotely sensed imagery.
Conclusions from the thermal data are likewise not possible at this point. It would appear that wet caves are more likely to be detected by these means. It is not yet clear what the GTD means, if anything, to the remotely sensed environment. There are several caves, Crystal Pit, Laberinto de las Tarantulas, and Hummingbird Cave in particular, that exhibited high GTDs. It is not clear yet if this is significant, and not only due to conditions specific to the sampling period. It is also doubtful that cave entrances with dense canopy coverage will be detectable due to the expected thermal shielding by the vegetation. One thing that is clear thus far is that the greatest temperature differences occurred during the early to mid afternoon.
Future Plans
In the computer labs at Indiana University we will use programs such as Idrisi and IMAGINE to manipulate the data and satellite images. We intend to determine weather spectral/thermal signatures exist for cave entrances or not. If such a signature exists we will search the rest of the image for similar configurations to locate heretofore-undiscovered cave sites in Belize



Bibliography


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1981 Prehispanic Agricultural Use of the Wetlands of Northern Belize. In Maya Subsistence: Studies in Memory of Dennis E. Puleston, edited by Kent Flannery. Academic Press.
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1972 Ridged Fields and Associated Features in Southern Campeche: New Perspectives on the Lowland Maya. American Antiquity 37(2): 228-239.
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1979 Geophysical Exploration for Ancient Maya Housing at Ceren, El Salvador. National Geographic Research Reports, pp. 645-655. Washington, D.C.


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