IB MArine science IA experiment with algae and salinity example. I need help doing an experiment related to this subject. Ideas or a brief summary will help a lot. Thank you and max points will be awarded

When new rock is added to an oceanic ridge, the magnetized strips on either side of the ridge are evidence of sea-floor spreading. this is because the rocks on the two sides of the ridge o are equal in width and in polarity are polar opposites oare magnetized vary in width but are equal in polarity