During my 12 years of experience as an ice core scientist on projects such as WAIS Divide Ice Core Project or the South Pole Ice Core (SPICE CORE) Project, measuring the appropriate density of an ice core prior to sampling the ice was of significant importance. Whether in the Desert Research Institute Ice Core Laboratory, the USGS National Ice Core Facility, or the Ice Core & Environmental Lab at South Dakota State University (SDSU), measuring the mass and dimensions of a core of ice was the first priority and its density the second priority. Now that I teach at a two-year college in northern California, I recognize that the concept of density is investigated regularly- in lecture, lab, or both- in Introductory (non-science majors) or the majors General Chemistry 1 courses. This post describes a short activity involving ice core density.
1. An ice core from the South Pole weighs 58.3 lbs. Based on the dimensions in the diagram below.
What is the density of the ice core in g/cm3? Density = _______________________
2. An instrument requires a minimum volume of 20.0mL per liquid sample. If a 3.00cm ice cube-shaped sample (each side = 3.00cm) is cut from the ice core, will the solid cubed ice sample provide enough volume of melted ice water to run an analysis on the instrument? (Remember: density of liquid water at room temperature = 0.997 g/mL)
Volume of melted sample is at least 20.0mL? Circle one: yes / no
Volume of melted sample: _________________
Students should be aware of the concepts of density (i.e. mass per unit of volume) as well as some dimensional analysis skills.
As an instructor, I typically use the Density of an Ice Core problem as a real-world application at the end of a investigating density activity or experimental report.
There is very little prep for this activity, other than the brief introduction to what an ice core is and what they are used for.
Developed by Tom Cox, Butte College