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The New World of 3D Geologic Mapping
Terry L. Pavlis and Kelsey A. Mason, Department of Geological Sciences, The University of Texas at El Paso, El Paso, Texas 79968, USA
ABSTRACT subsurface revolutionized hydrocarbon case study to illustrate how these high-
exploration and could do the same for resolution visualizations of Earth can dra-
Digital geologic mapping is now a fully field geology, where rich 3D information matically improve the ability to resolve
mature technology that dramatically is available from surface geology when geometric problems in the field. We then
improves field efficiency and problem there is significant topographic relief, yet speculate how this technology will reshape
solving capabilities. Basic digital mapping that 3D information is mostly lost in 2D field geology in the next 5–10 years.
is just the tip of the iceberg, however, in methods. In addition, we continue to
regard to new and approaching capabilities teach students flat-map techniques like THE 2D DIGITAL MAPPING OF
with true 3D mapping. The key advance is visualizing Earth’s surface through a top- TODAY AND THE NEW WORLD
the ability to easily construct high-resolu- ographic map, yet this abstraction of Earth’s OF 3D MAPPING
tion, photorealistic terrain models as a base surface is challenging for most students.
surface for 3D mapping using Structure Digital globes like Google Earth help A few years ago, we (Pavlis et al., 2010)
from Motion (SfM) photogrammetry ter- with this problem, but we now have far reviewed the history of technology that led
rain models, particularly through the aid of better options. to the modern generation of field data col-
unmanned aerial systems (UAS). We show lection systems for digital mapping, yet
how these technologies can aid field visu- In this paper, we consider the problem of seven years is an eternity in this field
alization and discuss how developing digi- geologic mapping and how 3D visualiza- of rapidly advancing technology. Two-
tal field workflows and 3D visualizations tion can aid that process. We emphasize dimensional digital mapping has now
will transform field studies, allowing the here the importance of the distinction become a fully mature practice with
resolution of problems that were impossibly between 3D geologic mapping and 3D numerous applications for field geology
complex without this technology. modeling of geologic features. Whole vol- (Mookerjee et al., 2015). Software and
umes have been written on the latter, but hardware issues remain, but there is no
INTRODUCTION 3D mapping as a data collection technique longer a doubt that paper mapping is out-
is still in its infancy (e.g., MacCormack et dated due to the inherent efficiency of digi-
The past 30 years have witnessed a revo- al., 2015; Buckley et al., 2016). To date the tal techniques and ability to share data
lution in digital technology that has led to primary work on 3D mapping has been in readily (e.g., Whitmeyer, 2012). Moreover,
astonishing changes in our lives, from the Europe and Australia, with most applica- increased mapping accuracy with GPS,
use of personal devices to advanced com- tions in engineering geology and geomor- routine access to multiple data layers, and
puting. Digital technology is also funda- phology (e.g., MacCormack et al., 2015; the nearly limitless scaling afforded by
mentally changing field geology in ways Buckley et al., 2016). This will soon change. digital maps allow for the resolution of
that will impact all geosciences. Digital We predict that 3D techniques will soon field problems that was impossible on
geologic mapping has been practical for fundamentally reshape all geologic field- paper maps. Nonetheless, these systems
more than 10 years (e.g., Pavlis et al., 2010), work in ways we have not even begun to are only the vanguard to a true revolution
and, although many cling to paper-based realize. In particular, we emphasize that that is upon us, 3D mapping.
workflows, that approach is now outdated new technology, Structure from Motion
and inefficient in comparison. Digital (SfM) photogrammetry in conjunction The Problem of Early 3D Methods
mapping also transforms a geologic map with unmanned aerial systems (UAS),
from a static, fixed-scale object to a aka drones, can allow routine construction For many of us, geologic mapping
dynamic, multiscale database complete of inexpensive, high-resolution, photoreal- through a 3D interface has been a dream
with the primary data used to construct it. istic 3D terrain models. These 3D surface since the first 3D computer visualizations
models can serve as a base for high-resolu- appeared on the scene. Two-dimensional
Digital mapping, however, is only the tion surface mapping that will allow con- digital mapping is largely a data manage-
beginning of an even bigger revolution that struction of a new generation of 3D geo- ment/collection variant on paper-based
is upon us from three-dimensional (3D) logic models at scales ranging from hand field geology, and therefore remains a
mapping and visualization. The geometry specimen to tens of kilometers. To support flat-map–centric approach to a problem
of geologic features analyzed in field stud- this claim, we begin with a review of the that is fundamentally 3D. Geologists first
ies is inherently 3D, and reliance on 2D limitations of widely used 3D visualiza- began to experience 3D mapping from
maps has handicapped advances in our tions of Earth’s surface in comparison to digital elevation models (DEMs) using GIS
understanding of the earth system. Three- capabilities of SfM models. We then use a software and digital globes like Google
dimensional geophysical imaging of the Earth and NASA’s Worldwind (DePaor,
GSA Today, v. 27, no. 9, doi: 10.1130/GSATG313A.1. © The Geological Society of America, 2017.
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