APPLICATION OF SURFACE MATCHING FOR IMPROVED MEASUREMENTS OF 
    
HISTORIC GLACIER VOLUME CHANGE IN THE ANTARCTIC PENINSULA 
M. Kunz**, J. P. Mills?, P. E. Miller”, M. A. King“, A. J. Fox’, S. Marsh® 
School of Civil Engineering and Geosciences, Newcastle University, UK (*matthias.kunz@ncl.ac.uk) 
®British Antarctic Survey, Cambridge, UK 
“British Geological Survey, Keyworth, UK 
Commission VIII, WG VIII/10 
KEY WORDS: Glaciology, Glacier Change, DEM/DTM, Photogrammetry, Surface Matching 
ABSTRACT: 
Climate records show that the Antarctic Peninsula is rapidly warming. Dramatic changes in ice shelf and glacier extent have been 
recorded over the last few decades. Mapping recent changes in the Antarctic Peninsula is relatively straightforward, as increased 
amounts of earth observation data become readily available for scientific purposes. However, long term measurements of volumetric 
changes within the region are rare and less is known of changes which have occurred over the second half of the 20th Century. 
Nonetheless, historical observations are available in the form of archival aerial stereo-photography. However, extracting information 
from historical data, i.e. to compare it to recent data, is not trivial, and to-date, this data source remains largely untapped, despite its 
rich potential. Often such imagery is stored in non-digital format and may have degraded over time. Other problems relate to 
insufficient metadata or ground control. Typically these difficulties result in poor registration of multi-temporal DEMs, which 
degrade subsequent measurements of surface change. This is one of the fundamental limitations of accessing archival datasets. In this 
research a least squares surface matching technique is introduced to overcome these challenges and achieve reliable registration of 
multi-temporal DEMs. Historical imagery acquired in the 1960s for two Antarctic Peninsula glaciers is processed to extract DEMs, 
which are subsequently compared to DEMs derived from modern ASTER satellite data and aerial photography. Through the surface 
matching approach, it is shown that the registration accuracy of the historical and modern-day datasets can be improved significantly. 
This enables precise quantification of glacier elevation changes on a multi-decadal time scale. Frontal glacier surface lowering of up 
to 50 m was observed over the last ~4 decades. Results of this study allow a better understanding of historical volumetric glacier 
changes of the Antarctic Peninsula and provide an efficient and automated method for improved DEM co-registration. 
1. INTRODUCTION 
The Antarctic Peninsula (AP) is one the fastest warming regions 
of the planet, and has been shown to be particularly susceptible 
to the effects of global warming. Increased air and sea surface 
temperatures have led to dramatic changes in glacier and ice- 
shelf extent in recent decades (Meredith and King, 2005; Cook 
and Vaughan, 2010). Over the last 50 years more than 85 % of 
244 observed glaciers showed retreat (Cook et al., 2005). An 
assessment of ice mass changes in the AP is very important to 
derive estimates of the region's recent and future contribution to 
sea-level rise. However, records of long-term glacier mass 
balance of the AP are rare, and are generally excluded from 
global projections of sea-level rise (Lemke et al., 2007). 
Repeated direct glaciological measurements are difficult given 
the harsh polar environment and mountainous terrain. However, 
airborne and satellite remote sensing offers an alternative tool 
for mapping of inaccessible areas. In particular, it has been 
noted that high-resolution satellite imagery, together with digital 
elevation models (DEM) derived from such imagery are well 
suited for the monitoring of glaciers (Oerlemans, 1998). In 
order to facilitate change analysis over extended time periods, a 
combination of historical and present-day stereo-imagery is 
ideal. 
The British Antarctic Survey (BAS) and the United States 
Geological Survey (USGS) hold large archives of historical 
aerial stereo-photography of Antarctica, which have been 
acquired since the 1920s, and which include extensive portions 
of the AP. The full potential of these historical datasets, 
spanning several decades, has not yet been explored, despite the 
demand for multi-decadal observations. This is primarily due to 
the substantial challenge of reconciling multi-source, multi- 
temporal and multi-resolution datasets in a manner which 
enables reliable change avoids the 
introduction of biases. Uncertainties, which may be introduced 
measurement and 
due to lack of ground control and other sources, will propagate 
into subsequent elevation measurements, leading to decreased 
accuracy in the assessment of elevation change. 
Such difficulties can largely be overcome through rigorous 
DEM co-registration, provided a suitable source of control can 
be derived. The dynamic nature of glaciated terrain and the 
difficulties regions making direct 
measurement of conventional ground control points (GCPs) 
near-impossible, and consequently, an alternative registration 
approach must be considered. The technique of least squares 
surface matching has been widely applied for registration of 
photogrammetrically-derived DEMs in the context of a number 
of accessing such