Inner core was found to be solid after observing the motion of P waves.
Explanation:
Seismologist Inge Lehmann, studied the seismic waves of an earthquake and discovered about inner core in the mantle layer of Earth. She States that there is a boundary of discontinuity between the outer and inner core of Earth.
She studied the travel of secondary and primary waves during an earthquake and how it flows at different shells of Earth's layer which helped her in finding about the inner core of mantle. She observed that the inner core is a solid layer inside the molten layer of outer core
Agriculture negatively affects reef ecosystems because the soil and the sea have a direct interaction of substances and minerals that can be altered with the intensification of agriculture.
<h3>What is agriculture?</h3>
Agriculture is a human activity that is based on planting seeds in the ground so that they develop and form plants that have uses such as food or others.
This is one of the oldest activities of humanity and has allowed communities to develop and create trading systems, wooden constructions, navigation, among others.
<h3>What impact does agriculture have on the reefs?</h3>
Agriculture generally takes place in coastal areas or near rivers because the composition of the soil must have certain minerals necessary for plants to grow.
Additionally, the components of the soil go underground to the sea and provide the water with different substances that contribute to marine life. However, the use of pesticides and other agricultural chemicals could reach the sea through runoff and affect the reefs.
Learn more about reefs in: brainly.com/question/364711
