UFV series starts with ‘grains of sand’ lecture

The poet William Blake mused about seeing all the world in a grain of sand. For University of the Fraser Valley geography professor Dr. Olav Lian and his student research assistants, it’s more a case of seeing how aspects of the physical world have changed over time by analyzing long-buried grains of sand.

The poet William Blake mused about seeing all the world in a grain of sand.

For University of the Fraser Valley geography professor Dr. Olav Lian and his student research assistants, it’s more a case of seeing how aspects of the physical world have changed over time by analyzing long-buried grains of sand.

As geochronologists, Lian and his associates view time very differently than many of us; they do this by studying the physical environment as it has changed over the millennia.

Lian is the featured speaker at this month’s installment of the University Lecture Series at UFV. He will speak at 4 p.m. on Wednesday, Jan. 26, in Room B121, on the Abbotsford campus. Admission is free and all are welcome.

Lian’s talk is entitled “Understanding the timing and nature of climatically-driven landscape change in western Canada by reading the landscape’s solar birth certificate.”

By understanding how the physical environment has responded to past changes in climate, it may be possible to predict the impact of future change on the stability of the fragile landscape.

To help find when these changes happened, and to be able to link them to intervals of past climate change, Lian uses a technique called luminescence dating, which allows one to date when grains of sand buried within a landscape were last exposed to sunlight – or when that landscape was last unstable.

In his lecture, he will explain the technique and, using examples, show how aspects of the physical environment have changed in the past, with emphasis on change that has occurred over the past 12,000 years. Lian will also explain how his data can help predict how the landscape might change in the future.

 “In order to be able to read the natural clocks found in the sand grains, one must have an understanding of what’s happening at the level of the atom,” explains Lian.

“By understanding this we can date sedimentary landforms that are only decades old, or up to a half-million years old and sometimes more, which is far more than can be done using radiocarbon dating. This is important as climatically driven landscape change is very much in the public awareness right now.”

Working together with their paleoecologist colleagues, who study ancient plant material preserved in landforms in order to reconstruct the nature of past environments, the researchers can find out when the environments in question occurred.

Doing so involves adventurous forays out into the field to collect samples, but also long hours in the near-total darkness of UFV’s Luminescence Dating Laboratory, as they prepare granular sand specimens for analysis, measure their luminescence properties, and run the resulting data through analytical software.

Trained as a physicist, Lian was a protégé of Simon Fraser University physics professor emeritus David Huntley, who, in the mid 1980s, invented a new method of counting electrons trapped within grains of sand in order to determine their age (the amount of time that had passed since the sand grains were last exposed to sunlight).

Now UFV is home to one of the few luminescence dating laboratories in North America, and currently the only Canadian laboratory of its kind west of Ontario. The highly specialized instrument used to measure the trapped electrons is made by Risø National Laboratory in Denmark.