Pictures movies

Freeze coring
Freeze Coring video Watch Dan's video of core retrieval and scraping
	Participants on pond setting up extraction tripod and freeze corer	Dan Nelson filling freeze corer with dry ice and ethanol, then closing it	Frozen condensation on outside indicates the box is already cold

Lowering corer through ice to sediments	Setting corer in place for 20-30 minutes.	Rigging tripod to extract corer after freezing in place for 20-30 minutes	Extracted corer with sediment attached. The pond sediment was relatively hard given it's a recently constructed pond.

Close-up of sediment before scraping.	Shot of front face	Ben Ho with corer	Dan Nelson with corer.

Cindy Adams with corer	Scraped sediment, we think the first white layer is Mount St. Helens ash from 1980.	Run 2 with leftover dry ice.	Core two extracted and back on top.

Frank Wilhelm scraping core two.	Cindy Adams and Connie Bozarth sectioning one of the frozen faces by hand - we didn't have access to a band saw in a walk-in freezer which is the usual way to section this type of core.	Close-up of sectioning, approx. 1 cm intervals.
Gravity coring (K-B corer)

Core with oxidized surface layer and worm tubes	Core with oxidized surface layer and worm tubes	Core with high organic matter at surface	Core with high organic matter at surface

Core with oxidized surface overlying reduced sediment	Entirely reduced material over clay base	Core tube transported	Extruding tray

Extruding tray	Dried and ashed sediment

Oxygen - Winkler titrations

Tim and Shannon adding MnSO4 and Alkali-iodide to fix oxygen	Floc formation in presence of oxygen	Ben ready to add acid to samples	Adding acid to liberate iodine from floc

Samples ready for titration	Cindy measuring out volume to be titrated	Titrating to straw colored end-point, then adding starch and discharging blue.	Shannon demonstrating her HACH MS5 and Surveyor to the class