Shield volcanoes are built by many layers over time and the layers are usually of very similar composition. The low viscosity also means that shield eruptions are non-explosive. There are two types of lava flows, pahoehoe which is a ropy type of lava that flows easily (low viscosity).
Weathering is a slow process. It takes thousands of years to erode a rock or land mass. This is going on today with our beaches and the rocks in the ocean.
<em>The focus is the place inside Earth's crust where an earthquake originates. The point on the Earth's surface directly above the focus is the epicenter.</em>
