Water works

“A significant lack of recent rain, and unusual heat during the month of September, led to the development of what is called “flash drought” across a large portion of the area. This essentially means that the short-term dryness and heat quickly overcame the long-term record wetness we experienced between April 2018 and the early summer of 2019. Although the heat has ended, significant rain has not yet been observed, so drought conditions persist.”  National Weather Service, October 8, 2019

east.vic.sm_qnt

If you live along the East Coast, chances are you noticed how dry it was in late summer and early fall, though this “flash drought” came as somewhat of a surprise after the extended sogginess of the previous year. Given the vital role that water plays in the lives of all living things, and its effects on non-living ecosystem components as well, the JE classes embarked on an intensive study of the many characteristics that make water so central to our lives.

We began by learning about physical and chemical properties of water. Positive, neutral, and negative buoyancy were introduced using numerous objects, and by learning to make and test reasonable predictions. Classifying objects by their float-ability was more challenging than many expected.

Experimenting with different densities and surface areas enabled more accurate generalizations, and we followed this with the classic penny boat challenge: “How many Abraham Lincolns can you keep afloat on your foil boat?” Results ranged from 0 to an astounding 200+. The cardboard boats that followed used wind power to move across our mini-ocean and featured creative detailing that tested the boats’ balance and waterproofing.

Having seen negative (sinking) and positive (floating) buoyancy in action, we attempted to achieve neutral buoyancy (within the water column). Our rock/balloon constructions mimicked fish and submarines with swim bladders and ballast tanks, with success dependent on finding just the right balance.

Next, it was time to review water’s different states of matter: solid, liquid, and gas. We enacted the difference in energy between these three states by playing a tag game where kids responded to a shouted prompt by finding others to quickly form an unmoving solid or flowing liquid, or by running away as a gas molecule. We also had fun trying to predict liquid capacity in different containers and playing with dry ice reactions.

Our typical introduction to the water cycle involves learning big words with big movements. Students jump off the classroom tables while shouting “Precipitation!”, “Runoff!” to the corners of the room, “Evaporation!” while climbing back onto the tables, and “Condensation!” while huddling together as cloud vapor.IMG_3224

This year, we added a technology component: augmented reality in the form of a MergeCube. This cool tool pairs with an iPad to create 3-dimensional views of all sorts of science content. For this lesson, we were able to make each stage of the water cycle play out in a miniature world complete with water raining onto and running off a mountain into streams and a lake, and then evaporating into wispy clouds. We reinforced these images with one more game, creating large cardboard dice showing different parts of the water cycle and designing multi-player game boards.

Throughout these water-based activities, we talked often of the lack of rain and how it might be affecting our campus. The small stream in the woods, which has its source in groundwater seeps, has sometimes dried up during extended droughts. This year it persisted throughout the fall, though with diminishing flow. Frogs, crayfish, and salamanders were found in the deeper pockets, but the vegetation along the banks hung limp and pale, lacking its usual fall vibrancy.

“Where is this water still coming from, if there’s no rain?” we wondered. The NWS report indicated that, in spite of the drought, deep groundwater remained at relatively normal levels, which apparently continued to supply us with enough water to keep the stream flowing. By October 15, however, still with no rain in sight, our region’s drought status had changed to severe. Groundwater levels were dropping.

A week later, relief arrived in the form of several days of drizzle and occasional heavy rainfall. The air along the newly recharged stream is pungent now and “finally smells like fall,” one frog hunter declared as he studied the current.090319-15

Our final water topic currently underway is a study of fish adaptations for underwater life. Given the erratic nature of our weather patterns this fall, and the tendency toward more extreme weather events and water quality impact as our climate warms, the challenge will be to design fish with adaptations to survive such changes. Mudskippers may once again have their moment.

Mangrove_mudskipper
Mudskipper, Wikimedia commons