True or false earth orbit is nearly circular

I guess that depends on what you mean by "nearly".
"Nearly" is one of those rubber words that means different things
to different people, and may even mean different things to the same
person at different times and in different situations.

I can tell you this much:

-- The Earth's orbit is an ellipse with eccentricity of  0.0167... .

-- At closest approach to the sun (perihelion, around January 3), the Earth
is about  3.3% closer to the sun than at its farthest (aphelion, around July 5).

-- When the true shape of the orbit is drawn on paper, its departure from
a perfect circle is not noticeable.

So to me, Earth's orbit is "nearly circular".  Your interpretation of the same
words may be different.

When seismic waves hit a fault, the waves are reflected off the fault. seismograph can detect these reflected seismic waves. geologists then use these data to map the fault's length and depth