Which of the following processes within the rock cycle operates at the earth's surface? plate tectonics
melting
weathering
pressure & heat?

Weathering

Explanation:

Weathering is a surface process which involves the chemical decomposition and physical disintegration of rocks to form sediments and soils. Weathering is a surficial process which is aided by agents like water, wind, glacier and gravity. All of these are driven by the external processes of the earth.

The action of running water helps to alter a rock chemically. Also, water can cause abrasion and wearing away of the rock body.

Wind blows and carries dust and light soil materials from one place to another. Wind blown dust from part of the earth can travel to far reaches of the globe. Wind is driven by the earth system of air masses from one place to another. It acts in the surface of the earth.

Glaciers are prominent in polar regions of the world. Thick layers of ice and snow helps to sculpt the surface of our blue planet from time to time. The process of glaciation is a surficial one.

Gravity helps to move large masses of earth. The gravitational force that acts from places to places helps moves materials from one place to the other.

All of these combines to alter the surface of the earth. The surface processes derieves the bulk of their energy through solar radiation. It is incoming radiation that warms the surface of the earth and drives the whole water cycle. The water cycle presents how water is transformed from through phases.

Without weathering on the earth surface, sedimentary rocks would not have been formed.

Other process like melting, pressure and heat are driven by the internal heat Engine.