Imagine that you could drain the Atlantic Ocean to explore the mid-oceanic ridge which runs roughly north to south from pole to pole. What would the ridge area look like as you approached it and then walked across it? Tell me what you see. Describe what is happening at the MOR in as much geologic details as possible. Discuss what is happening in terms of plate tectonics.
On a close view, the Atlantic Ridge appears like an elongated mountain chain. This mountain runs along a curved path for approximately 10,000 miles as measured. The ridge is equidistant from the two continents it separates with the width of the mountains forming the ridge being 1,000 miles. As seen, some islands have been formed by these mountains some including Azores, St. Helena, Ascension, and Tristan da Cunha. On giving a closer look, the mantle seems to rise towards the surface resulting in lowered pressure below the ridge. This resulted in the hot rock melting with basaltic lava rising on the surface. The flow of the lava makes the plates drift further apart from each other and the pillow lava can be observed forming a fresh ocean lithosphere at the ridge. On testing, this proved evident as on either side, the crustal material was younger compared to the ones further away from the ridge. This occurs through a process known as seafloor spreading. Moreover, slight earthquakes can be experienced in these regions. The basin is believed to be widening each year at approximately 0.5 to 4 inches annually. Though it looks dangerous plant life is sustainable as algae can be seen flourishing in the region.
If North America and Africa were once joined as part of Pangaea, what does the MOR have to do with the fact that they are now separated by the Atlantic Ocean?
Though previously existing as a part of Pangaea, North America and Africa split due to divergent boundaries. These boundaries make continents move further away from each other thus forming new continents. The Mid-Atlantic Ridge serves as the best known divergent boundary with its slow movement of about 4 inches annually making the two continents move further away from each other. This happens through seafloor spreading which is the underwater eruptions happening forcing the plates to further drift away from each other.