Title: Grandiose Green Glaciers Gradually Melting Like Mad!

PurposeResearch question: Does the presence of organisms affect the rate of melting of ice? Does the density of the presence of this organism affect the rate of ice melting?

Hypothesis If the presence of organisms affects the rate of ice melt, then the mass of the organisms present in the ice will increase the rate of ice melting because of increased pigmentation of the ice. The darker pigmentation of ice results in an increased absorption of sunlight, which exacerbates the melting rate. Also, the melting of the ice causes organic matter to decay and release carbon dioxide and methane, a heat trapping gas. This effect influences and contributes to global climate change beyond the factors related to ice melt alone. In the experiment, we will focus on the rate of ice melt as a result of the presence of organisms in the ice. The darker pigmentation of the ice results in an increased absorption of sunlight by absorbing, rather than reflecting, more wavelengths of solar radiation. This exacerbates the melting rate by allowing more of the solar energy to be converted to atomic movement, heat, thus causing the ice to melt faster.

http://blogs.ei.columbia.edu/2012/12/06/how-the-warming-arctic-affects-us-all/

Variables

Independent- The density of organisms per ice sample

Dependent- The rate of ice melt

Control- Temperature of the ice, mass of sample, salt concentration of ice, amount of time ice is allowed melt, the intensity of light

Materials

● Aquatic Plant Matter ● Ice cube tray● large tupperware container● Blender● Water with a 3.5% salt concentration (35 g/L)● 400 mL Beaker

● Freezer● 18 plastic cups● Electric Balance● 3 100 mL Beakers● Stopwatch● Forceps● Pencil● Paper

Procedure

(Note: be sure to rinse out all glassware before use to remove excess dust that may affect experimental results.)

1. Obtain an organism sample from a local waterway using a dip-net. Collect as much live green matter as possible inside a tupperware container with enough water to keep the sample saturated.

2. Strain the live media from the water by picking it up with a stirring rod.

Be sure to always wear safety glasses during the lab!

3. Move organic matter into a blender. Pulse until completely homogenized (about 1:00 min.) 4. Remove sample from blender and transfer to a flask labeled “Live Organic Matter.” Set aside for

later use.5. Prepare 1,000 mL of distilled water in a 1000 mL beaker. Record volume.

a. Mass 35 g of salt, and then add to the beaker. Record. b. stir until fully dissolved.

c. use 6 smaller beakers and fill with 150 mL per beaker using a graduated cylinder. 6. Mix a 5% concentration suspension of salt water and organic material/

a. Weigh out enough organic material for a 5% g/g concentration by massing 7.5 g of organic matter.

b. Add to the 1st 150 mL salt water beaker. Label this beaker “5% organic matter.”c. Mix until homogenous.

7. Repeat step 6 and 7 using the measurements for each concentration (10%, 15%, 20%, 25%).8. 10% of organic material is calculated by calculating 10% by weight of 150 g of water. Therefore,

the mass of organic material for each concentration is 15 g for 10%, 22.5 g for 15%, 30 g for 20%, 37.5 g for 25%.

Beakers with salt water and various concentrations of organic matter

9. Pour each beaker with the different concentrations of organic matter into each of 6 ice cube trays. Make sure that the water/organic solution is equally distributed in the spaces in the trays.

10. Freeze cube trays until water is completely frozen. 11. Remove 1 control ice cube from tray. Also remove 1 5%, 10%, 15%, 20%, and 25% ice cubes

from their trays. Place each cube for the 1st trial in cups using forceps.12. mass each ice cube immediately after removing from their trays, making sure that you’ve

zeroed the scale with the cup before massing the cube.(Note: Be sure to start the stopwatch for each sample as soon as they are weighed and put into their respective cups.)

13. Allow ice cube to melt for 1 hour using a stopwatch to keep track of time.

Ice cubes ranging from 0%-25% org. matter concentration (right to left) undergoing trial.

14. After time is up, remove any remaining ice solid from the trial 1 cups using forceps. (Try your best to remove as much solid ice as possible, because the cube may break up when you try to remove it.)

15. Measure the volume and mass of ice melt water by transferring the sample from the cup to a 50 mL graduated cylinder. Be sure to zero the graduated cylinder on the electric balance before pouring in the melt water.

16. Record the mass of the melt water in grams, as well as the volume in mL in the table.17. repeat steps 15 and 16 for each concentration of organic matter.18. Record all data in a table. Compare results to the control ice sample. 19. Repeat all steps (1-18) 4 to 5 times, being sure to record your results for every trial.

Control Table

Volume of distilled water (in mL) 1000 mL +/- 25mL

Mass of salt (in g) 35 +/- .05g

Volume of salt mixture for each concentration mixture (0%, 5%, 10%, 15%, 20%, 25% respectively in mL)

150 mL of salt water for each concentration +/- 1mL

Mass of organic material added for each concentration mixture in grams (0%, 5%, 10%, 15%, 20%, 25% respectively)

0%- 0 g, 5%-7.5 g, 10%-15 g, 15%-22.5 g, 20%- 30 g, 25%- 37.5 g (+/- .05g for all)

Melting time (in hh:mm:ss) for each trial (0%, 5%, 10%, 15%, 20%, 25% respectively)

1:00:00 +/- .14s (1 hour) for each trial for all concentrations

Original mass of 0% of organic matter in ice cubes (in grams)

24.31, 25.00, 23.13, 24.70, 25.60 (+/- .05g)

Original mass of 5% of organic matter in ice cubes (in grams)

23.16, 22.02, 23.13, 22.17, 23.02 (+/- .05g)

Original mass of 10% of organic matter in ice cubes (in grams)

26.05, 24.44, 23.15, 22.43, 27.79 (+/- .05g)

Original mass of 15% of organic matter in ice cubes (in grams)

24.33, 21.41, 22.26, 23.19, 24.00 (+/- .05g)

Original mass of 20% of organic matter in ice cubes (in grams)

22.03, 25.85, 25.59. 21.28, 22.37 (+/- .05g)

Original mass of 25% of organic matter in ice cubes (in grams)

26.98, 26.29, 26.69, 27.43, 27.47 (+/- .05g)

Concentration of live organic matter in 5 ice samples and their volume/mass of meltwater

0% Concentration(in mL/g) (CONTROL)

5% ConcentrationMelt water (in mL/g)

10% ConcentrationMelt water (in mL/g)

15% ConcentrationMelt water (in mL/g)

20% ConcentrationMelt water (in mL/g)

25% ConcentrationMelt water (in mL/g)

Trial 1 * * 14 mL/13.60 g (+/- .5 mL/ .05g)

11.5 mL/10.23 g (+/- .5 mL/ .05g)

15 mL/13.55 g (+/- .5 mL/ .05g)

11 mL/9.85 g (+/- .5 mL/ .05g)

Trial 2 14 mL/12.56 g (+/- .5 mL/ .05g)

14 mL/13.20 g (+/- .5 mL/ .05g)

14 mL/12.52 g (+/- .5 mL/ .05g)

14.25 mL/12.95 g (+/- .5 mL/ .05g)

18.5 mL/17.11 g (+/- .5 mL/ .05g)

19 mL/17.73 g (+/- .5 mL/ .05g)

Trial 3 13 mL/12.18 g (+/- .5 mL/ .05g)

13 mL/12.25 g (+/- .5 mL/ .05g)

15 mL/13.86 g (+/- .5 mL/ .05g)

17 mL/15.42 g (+/- .5 mL/ .05g)

18 mL/16.57 g (+/- .5 mL/ .05g)

16 mL/15.07 g (+/- .5 mL/ .05g)

**Trial 4 16.5 mL/15.42 g (+/- .5 mL/ .05g)

14 mL/12.78 g (+/- .5 mL/ .05g)

15.5 mL/14.31 g (+/- .5 mL/ .05g)

15.25 mL/14.99 g (+/- .5 mL/ .05g)

17.5 mL/16.33 g (+/- .5 mL/ .05g)

***5 mL/14.28 g (+/- .5 mL/ .05g)

* samples were lost.

**This trial exceeded the trial time by 10 minutes before solid ice was removed.

***cup containing melt water was spilled.

Percent meltwater (g/g) for each concentration of ice sample for 4 trials

* see chart for uncertaintyPercent Meltwater (meltwater in grams/initial mass of ice)

Trial 1 Trial 2 Trial 3 Trial 4 Average

0% 54.30% +/- .6% 49.30% +/- .6% 60.20% +/- .6% 54.60% +/- 1.8%

5% 57.06% +/- .6% 55.25% +/- .6% 55.51% +/- .6% 55.94% +/- 1.8%

10% 52.20% +/- .6% 54.08% +/- .6% 61.79% +/- .6% 51.49% +/- .6% 54.89% +/- 2.4%

15% 42.04% +/- .6% 58.17% +/- .6% 66.49% +/- .6% 62.45% +/- .6% 57.29% +/-

2.4%

20% 61.50% +/- .6% 66.86% +/- .5% 77.86% +/- .5% 72.99% +/- .5% 69.80% +/- 2.1%

25% 36.50% +/- .7% 66.42% +/- .5% 54.93% +/- .6% 51.98 +/- .6% 52.45% +/- 2.4%

ConclusionOur hypothesis was proven mostly correct, with most of the data confirming it and some of the data creating complications. Our results show a general trend of the percent of meltwater increasing as the concentration of organic matter (and therefore organisms) increases. However, the exception to the trend is the trials for the 25% concentration of organic matter. The general increase in meltwater due to increased organic material can be explained by a phenomena observable in melting glaciers; the warming of the Earth causing glaciers to melt allows a layer of permafrost containing bacteria and other microorganisms to become active. As the layer of permafrost begins to decompose, it is warm enough for the microbes to respirate and release compounds such as methane. Methane is a known greenhouse gas that has 20 to 25 times the warming power of CO2. (wunderground.com) The chain reaction set of by organisms as the layer of permafrost melts inevitably results in an even quicker melt rate as the produce gas products that warm the ice even further. Higher concentrations of organic matter in the ice of the experiment would indicate a higher number of organisms present in the ice. As our ice cubes melted, the organisms became active and released CO2 and methane as products of their respiration. This in turn increased the amount of meltwater produced after one hour of melt time. There was anywhere between a 5%-11% increase in meltwater for a 5% higher concentration of live medium. The difference in the % meltwater between concentrations tended to be higher between those with higher concentrations of organic matter, such as between 15%-20%. This suggests that the rate of melt increased exponentially with increasing amounts of organisms. This result makes sense, as more organisms producing more gas would melt the ice at an exponential rate, not a linear one. The exception to this explanation would be the trials for ice cubes with a 25% concentration of organic matter. We could not find a scientific explanation for this result. A logical conclusion would be that because the samples contained less water as compared to the other samples, the meltwater obtained was less because live media comprised so much of the sample. There also could have been some measurement errors that resulted in skewed results. For example, in trial 4 the cup containing the 25% concentration melt water was spilled, resulting in a measurement with less meltwater than would otherwise be recorded. It is worth mentioning some other issues that were encountered during the experiment.

Samples for trial 1 for 0% and 5% concentrations were accidentally lost before measuring. A whole separate trial for all concentrations was also lost and was excluded from the results, due to an error with the timing device that paused. The data was omitted because the trial time would not be constant and would make the data unreliable. Trial 4 was left to melt 10 minutes too long, but the data was still recorded when the mistake was noted so that there would be enough data to make adequate conclusions.