Diagram of continental crust and ocean level in the Hadean and Archean eons, according to a plausible geophysical model.<br>A possible evolution of early Earth landscape. (a) In the early Hadean, the ocean was likely shallow (∼1 km) because most of water was yet to be degassed from the mantle. Continental crust was absent, but the activity of mantle plumes was probably high to create quite a few ocean islands. (b) In the mid-Hadean, a substantial mass of continental crust started to appear. The growth of continents could outpace that of ocean, and some fraction of continents could have been exposed. Ocean islands continued to provide exposed land though they may not have existed in abundance. (c) Around the late Hadean to the early Archean, the mantle is likely to have been full degassed, resulting in a deep ocean. Even with the mass of continents grown to the present-day level, continents were below the sea level, making ocean islands the sole source of exposed land. In this illustration, distinction between lithospheric and asthenospheric mantle is omitted for simplicity. Additionally, the operation of plate tectonics is assumed at all panels, but the subduction of oceanic crust is omitted for simplicity.
Jun Korenaga
CC BY-SA 4.0
<cite style="font-style:normal">Korenaga, J (2021). "Was There Land on the Early Earth?". <i>Life</i> <b>11</b> (11): 1142. <a href="https://en.wikipedia.org/wiki/Digital_object_identifier" class="extiw" title="w:Digital object identifier">DOI</a>:<a rel="nofollow" class="external text" href="https://doi.org/10.3390/life11111142">10.3390/life11111142</a>.</cite>