Final answer:
The artwork created by Robert Smithson in 1970 is known as The Spiral Jetty. It is a significant piece of Land Art located in the Great Salt Lake, Utah, demonstrating the link between art and the environment.
Step-by-step explanation:
The name of the artwork created by Robert Smithson in 1970 that is an earthwork/site-specific art is The Spiral Jetty. This piece is a site-specific work of Land Art or Earth Art located in the Great Salt Lake, Utah.
Constructed using rocks and earth, Smithson's creation is a spiral-shaped relief in the lake bed that stretches out 1,500 feet into the lake. It can be best appreciated from an aerial viewpoint and is constantly changing due to the fluctuating water levels, illustrating the dynamic relationship between the artwork and its environment. Spiral Jetty is an iconic example of a work that is inextricably linked to its surrounding landscape.