At what depth on Mars would the atmosphere have equal pressure of that on Earth?

Nasa has a atmospheric model of mars:
$$0.699 *e^{-0.00009 h} $$

A naive application of this model, solving for a pressure of 101 kPa, gives a depth of -55 km.

The Armstrong limit depth (at which water boils at body temperature) is -24km

The model assumes constant temperature, and gravity (it doesn't correct for the fact that at 55 km below the surface you would be well into the martian mantle, and deep enough for a measurable difference in gravity)

These depths are not achievable with current technology. The deepest mines on Earth are about 4km deep, and even the Kola superdeep borehole only managed 12km