The top layers of the cliffs were fine and silty sand where volcanic ash landed. This rich ash has helped form the Taranaki dairy lands. The "language of volcanoes" is the interplay of the earth and water moving, Mrs Stegmann says.
The geometric forms over which the moving image flows are inspired by two big faults that run out to sea and form a graben, a geological term for a large portion of the earth's crust that has dropped down between two deep active fault lines.
Adding to the installation are the folders for maps that Mrs Stegmann found at the Sustainable Whanganui shop at the Resource Recovery Centre.
The named areas on the folders expand the language of the installation.
Mrs Stegmann says she is "heart-sore" at what is happening to the black sand beaches.
"New Zealand is beautiful and it is being exploited economically. These black sands may not be there for long."
Learning the Languages about Volcanoes, Rena Starr's Gallery, 62 Guyton St from today to Sunday, 11am-4pm.