June 4, 2012
Over the River and Through the Cave: Our Journey to Yok Balum
Entrance to Yok Balum Cave. Photo by Lindsey Estes.
Ever since our group first received our trip itineraries, we knew that we would be hiking through the jungle to Yok Balum Cave for our last day in Toledo. Adding to the excitement, we would also be entering the cave itself; we were even required to bring helmets and headlamps along. What could be more thrilling than checking out some amazing cave formations while trying to avoid hitting your head on one? Even though we were told to expect a pretty rigorous hike up to the cave, I was up for the challenge. When the day finally arrived, though, I was hit with the reality of enduring the toughest and most rewarding hike I have ever experienced.
On the day of the hike, we started early so we could get up to the cave during the cooler part of the day. After rounding up our helmets, hiking boots, and plenty of DEET, we jumped in our van and headed to the village of Santa Cruz, the same place where we had been a few days before to do our service learning. The trail to Yok Balum started just beyond the schools soccer field. Then, after meeting the two Maya guides that would be leading us up the trail, we set off towards the cave. After hiking for about an hour and a half, which included crossing the Rio Grande and a pretty steep climb up to the actual entrance of the cave, we had reached our destination. We were greeted at the cave entrance by a really interesting formation that looked like a jaguar paw, which, as our guides told us, is what Yok Balum translates to in the local Maya dialect. Then, our guides did a final check on our helmets and headlamps, and we entered the cave.
Stalactite formations in Yok Balum.
Inside the cave was breathtaking. We saw stalagmites, stalactites, and countless other formations that looked like they came from another planet. The same formations that were so beautiful to look at also turned out to be pretty useful hand holds during our hike and climb through the cave. About halfway through the cave, we found places to sit down, and our guides had us turn off our headlamps; we were plunged into complete darkness. This almost surreal experience helped me to understand why the Mayans viewed caves like Yok Balum as such sacred places. We spent a few more minutes in the dark before turning back on our headlamps and proceeding through the cave, now joined by the bats that inhabited the cave. After spending about an hour in the cave, we emerged back into the jungle and made our way back down the trail.
Looking back, this hike was definitely one of the highlights of my experience in Belize. Between the uniquely challenging hike through the jungle and the amazing sites within the cave, I don’t think I will ever forget my Yok Balum experience. I also think that sharing this journey brought our class a lot closer together; on a related note, I would like to send a special thank you to everyone that motivated me when the going got tough during those last few hills. Relatively few people get the change to traverse this spectacular cave, and having the opportunity to do so increased my appreciation for my unforgettable Belize experience.
Lindsey and Sydney take a break from cave hiking.
Lindsey Estes is a junior from Federal Way, Washington. She is currently pursuing a B.A. in Environmental Studies with a minor in Political Science.
June 2, 2012
Water bonds more than just molecules!
The Blue Creek Cave is arguably one of the largest underground cave systems in the world. The creek runs through a cave that is more than five miles in length and is located in the Blue Creek village within the Toledo District of Southern Belize. Geologically speaking, the creek derives from an underground source that slowly made its way through limestone boulders, which created the cave’s configuration. After years and years of existence, stunning calcium carbonate formations, otherwise known as stalagmites and stalactites, line the walls.
Location of Blue Creek Cave in the Toledo District of Southern Belize.
Blue Creek plays an essential role in the local community as it serves as a fresh water resource for nearby residents. Archaeologists also find the cave significant because they have recovered several ancient Mayan ceramics and other artifacts from inside. Tourists, on the other hand, including myself and my classmates, take interest in the Blue Creek Cave for the caving experience.
On Friday afternoon, we drove over to Blue Creek village to begin our caving adventure.
Before arriving at Blue Creek village, my classmates and I were expecting a ‘mild’ trek to the cave and an ‘easy-going’ swim through it. However, we actually experienced the complete opposite…
First of all, the trail to the cave’s entrance was not as clear-cut as we were anticipating. The latter half of the hike involved quite a bit of rock climbing as well as crossings over slippery stones and stretches of creek water. Needless to say, we were already soaked and muddy before even reaching the mouth of the cave. After about 40 minutes of strenuous trekking we finally arrived at the cave’s opening. There, we stripped down to our bathing suits and strapped on some lifejackets and cave helmets.
Upcoming senior, Lindsey Estes, and author at the start of their Blue Creek Cave adventure. Photo courtesy of Ticia Lee
Our guides, Manuel and Rosalio (also our designated van driver), jumped into the waters and led us into the darkness. After all, only the first 15 or so feet of the cave are exposed to outer elements such as natural sunlight. As we journeyed further into the pitch-black cave with our trusty headlamps, we noticed that the flow of the creek was quickly picking up. What had begun as a stroll through a lazy river stream suddenly turned into a challenging struggle through rapid currents. As we zigzagged through the cave in the opposite direction of the current’s flow, we relied on one another for strength and support. I remember that at some points, my entire body was horizontal to the water’s surface while I was hanging on to the edge of slimy limestone for my life.
In between our attempts to catch our breath, we marveled at areas that displayed embedded stalagmites and stalactites. They were quite a sight to see especially because I never expected to find such unique structures in a place that never sees broad daylight. These stalagmites and stalactites form when water drops accumulate and deposit calcium salts. The difference between the two types of calcium carbonate formations is that the stalagmites rise from the floor of the cave while the stalactites hang from the roof of the cave.
A glimpse at some of the calcium carbonate formations spotted in the cave. Photo by Ticia Lee.
We slowly made progress as we proceeded to struggle pass the strong currents, gripping onto slippery limestone and propelling ourselves across the rapids as fast as we could. After reaching the second of five waterfalls, it was finally time to head back. As you can imagine, the trip back was nothing like the trip there. When we were ready, we let go of the walls and effortlessly drifted back to the opening of the cave.
By the time we reached the mouth of the cave, over an hour had passed. All of us were relieved to see some sunlight and to step onto stable land.
The experience as a whole was truly a bonding one because it not only tested our trust in our guides but also our trust in each other. If it were not for some of my classmates’ and both of our guides’ help, the powerful currents could have violently swept me back down the creek before finishing the tour. Looking back on that day now, I think we all can have some good laughs about how ridiculous our struggles were. It was one of those unforgettable stories that I will always retell to my family and friends back home.
Ticia Lee is a sophomore majoring in Public Relations and minoring in Environmental Studies. Upon graduation, she hopes to work for a company that effectively communicates environmental awareness to the general public. Being a city girl from San Francisco, Ticia enjoys spending time in the great outdoors as much as she can. This is her second time participating in one of USC Dornsife’s Problems Without Passport programs.
May 18, 2012
Underground Evidence for Maya Collapse
The Maya, a Mesoamerican society considered the most advanced Native American civilization of its time, began a complex development around 2000 B.C. Divided into two main periods, Preclassic and Classic, the Mayans underwent a relatively abrupt collapse between 750-900 A.D., known as the Terminal Classic. The cause of rapid decline of such an intricately developed people has since been a topic of interest. One theory in particular is growing increasingly irrefutable: climate change. In 2007, James W. Webster et al., used stalagmite evidence from the Macal Chasm, a cave in Belize, to demonstrate that climate change, specifically drought, may have played an integral role in the Maya demise.
Stalagmite formation in Yok Balum cave, Belize. Photo by Dan Killam.
Stalagmites are formations resultant from the dripping of mineralized solutions into caves through the overlying soil and subsequent deposit of calcium carbonate. Because of the CO2 present in the atmosphere, rainwater is naturally acidic, and thus dissolves calcium carbonate when percolating through calcium carbonate rich soils. Upon entering a cave, water’s concentration of calcium carbonate is so high that some precipitates out when the water drips through the cave, forming stalagmites. Webster et al. used several proxy factors from stalagmites to indicate the climate in Belize during which the stalagmite sample was formed, including reflectance, color, and luminescence of the sample, as well as carbon and oxygen isotopic records.
Luminescence “is produced by organic acids and so is related to productivity in the soil and vegetation cover above the cave [ . . . ] as a proxy for availability of moisture” (Webster et al. 9). The particular sample from the Macal Chasm demonstrates long periods of higher luminescence—moisture—with interjecting periods of lower luminescence—drought. Color has a strong correlation with luminescence. Browner color indicates the accumulation of dust on the stalagmite, implying that there was not enough water in the cave to keep the formations free of dust (9). Dryer climates, as indicated by the color measurements, occurred during the same time periods as lower luminescence, indicating drought. Reflectance also correlates to the two aforementioned values, but is a less dependable indicator because calcium carbonate in general does not reflect much light. Combined, however, the three measurements consistently agree on times of more moisture and times of less moisture, and overall suggest several periods of drought that the Maya faced.
Another important variable measured from the stalagmites are the oxygen and carbon isotopic records, which point to different climate indicators. Oxygen isotopic records signify the amount of rainfall at the time of the stalagmite formation. Oxygen has two common isotopes, oxygen-16 and oxygen-18, the latter being heavier. The stalagmite sample used by Webster et al. was very near the entrance of the cave, meaning a higher likelihood of exposure to outside climate conditions. Because of its lower weight, oxygen-16 is more readily evaporated from the stalagmite than oxygen-18, which leaves behind more oxygen-18 and thus a higher value of the oxygen isotope ratio. More evaporation would occur from the stalagmite in drier climates, so a higher isotopic ratio value suggests less rainfall. The carbon isotopic record, on the other hand, indicates the amount of vegetation present over the cave. Three common isotopes of carbon are carbon-12, carbon-13, and carbon-14, with their weights increasing respectively. Vegetation prefers to use the lightest of the three isotopes because capturing it requires the least amount of energy; therefore, a cave covered with large amounts of vegetation, indicative of a generally wetter climate, would have a lower carbon isotopic ratio. Because both isotope ratios are ultimately suggestive of rainfall levels, they are strongly correlated. The Webster et al. data records lower values (wetter climates) and higher values (drier climates) of each isotope ratio during the same time periods. The matching records greatly increase the dependability of the data.
Data from Webster et al comparing several stalagmite-based datasets during the main periods of Maya civilization.
The Webster et al. data for all five of the proxies measured, shown above, demonstrates remarkable levels of agreement for periods of wet and dry climates. Webster et al. identifies 4 significant periods of drought from the data. The first, occurring around 141 A.D., corresponds to the Preclassic Abandonment, which is archaeologically recorded as a cessation of construction in several major Maya locations (2). The next evident drought comes around 517 A.D., which marks the beginning of a period described as the Maya Hiatus, archaeologically recognized as a period with a decrease in the amount of dedication of monuments. The third drought comes as a series at the peak of the Maya Classic Period, when it is thought that the Maya were at their highest population, and thus, extremely dependent on water for agriculture and consequently vulnerable to drought. The droughts ranged from 780-1139 A.D., with the Maya civilization thought to be completely collapsed around 910 A.D. The fourth and final significant drought identified by Webster et al. around 1472 A.D. comes after the Maya Terminal Classic, but is significant for another reason: it was recorded in Maya Books (14). The confirmation of this portion of the data amplifies the reliability of the rest of the data projected on the Maya Preclassic and Classic periods.
While no theory on the Maya collapse is unquestionably conclusive, strong evidence is building that climate change in the form of drought imposed a significant burden on the civilization, given their degree of dependence on rainfall. Though the collapse of the Mayan society was likely a combination of multiple factors, and perhaps a snowball effect of all the factors combined, it is becoming progressively clearer that climate change as a cause should not be dismissed.
Source:
Webster, James W., George A. Brook, L. Bruce Railsback, Hai Cheng, R. Lawrence Edwards, Clark Alexander, and Philip P. Reeder. “Stalagmite Evidence from Belize Indicating Significant Droughts at the Time of Preclassic Abandonment, the Maya Hiatus, and the Classic Maya Collapse.”Palaeogeography, Palaeoclimatology, Palaeoecology 250.1-4 (2007): 1-17. Print.
Sydney MacEwen, an LA native, is an upcoming Junior pursuing a BS in Environmental Studies and a minor in Geological Hazards. This is her first trip to Belize. She’s particularly interested in climate change and related policy. She hopes to pursue a Master of Arts in Environmental Studies following her undergraduate education.