Lars Eriksen Moen

My G-grand father is listed as Lars Eriksen Moen on the passenger list for the Bark Rjukan. Leaving Skien on 19 April 1868, arriving Quebec 13 June. His father, I believe, was Lars Eriksen. So I have no idea why he used the name "Moen". His wife's name was, Liv Andrea Johnsdtr. The family story is that their 3 children contracted measles, aboard ship, died, and were buried at sea. G-grandparents were later found in the 1870 Iowa census with a 1 year old daughter. My grandmother born in 1872. Lars then was known as Louis Ericksen. Maybe the census taker couldn't understand his Norwegian.....