Inconsistency between topographic survey and Google Earth
It's almost certainly a difference in the UTM zones.

In most zones, the minimum easting value is 160,000 mE and the max is 834,000 mE (at the equator). People sometimes use the 'wrong' zone (i.e. not the zone that the location is actually in) if it's more convenient to use a neighbouring zone for some reason. For instance, maybe I have coordinates for 100 points but a few are in a neighbouring zone; it's probably easier to tolerate the location inaccuracy than to reference them to a different UTM zone.

The other thing that can create discrepancies is different datums (e.g. WGS84 in Google Earth, and some other probably local datum for your survey), but that's not what's going on here. 

To sum up, it looks like the coordinates you were given are referenced to Zone 19K, to the east of Zone 18K, so the easting is smaller than the usual minimum. The correctly referenced Zone 18K coordinate is the one in Google Earth.

Last thing: I just want to connect with this related question.



EDIT: Conversion

Converting to the correct coordinates is a little risky without knowing exactly how the original coordinates were arrived at. But if they were indeed simply given in UTM Zone 19, then a round-trip conversion via lat-lon shows that they are equivalent to 781493.139 mE, 8177491.483 mN in UTM Zone 18. 

We can confirm this with PyProj using the zones' EPSG codes:

&gt;&gt;&gt; import pyproj
&gt;&gt;&gt; x, y = 140800, 8176337  # Zone 19S we think
&gt;&gt;&gt; utm18_wgs84 = pp.Proj(init='epsg:32718') 
&gt;&gt;&gt; utm19_wgs84 = pp.Proj(init='epsg:32719')
&gt;&gt;&gt; pyproj.transform(utm19_wgs84, utm18_wgs84, x, y)
(781493.1384182497, 8177491.482738381)


So, if that's what originally happened, these new coordinates are what you want.