Update depth taper (Portland-Tualatin basins)
Portland-Tualatin basin requires adjusted USGS basin model depth tapers.
We want to scale from 2-3 km for z2p5 and 0.4-0.5 for z1p0.
Need to add taper depth data to geojson properties.
At present P-T basins work ok there just isn't much data in the upper half of the hard-coded taper interval.