This award is for support for the measurement of electrical and optical properties of the Siple Dome ice core. The electrical methods can be used to determine the concentration of the hydrogen ions and the concentration of a weighted sum of all ions. The electrical measurements can resolve features as small as 1 cm. The albedo of the core is also measured with a laser system that can resolve features as small as 0.5 cm. The high spatial resolution of these methods makes them ideal for resolving narrow features in the core, which can be missed in larger composite samples. The measurements will be particularly useful for assisting to date the core and to identify short duration features in the record, such as volcanic eruptions. These measurements will also provide useful information for assessing the temporal variability of Holocene accumulation rate and atmospheric circulation.