1Remote sensing as a non- invasive method for study of the past permafrost features. Wielkopolska, Poland case study

Remote sensing as a non- invasive method for study of the past permafrost features.

Wielkopolska, Poland case study

Marek Ewertowski

Andrzej Kijowski

Marcin Słowik

Wydział Nauk Geograficznych i Geologicznych

Uniwersytet im. Adama Mickiewicza w Poznaniu

2Remote sensing as a non- invasive method for study of the past permafrost features. Wielkopolska, Poland case study

Introductions• Permanently frozen ground (Permafrost) – 24% of the

area of northern hemisphere (French 2007)

• Intensive transformations related to climate changes

• It is necessary to investigate of the direction and intensity of these transformations

• Investigation of both modern and Pleistocene permafrost

3Remote sensing as a non- invasive method for study of the past permafrost features. Wielkopolska, Poland case study

Main objective• to propose a non- invasive method for study of the

past permafrost features with the use of remote sensing, Geographical Information Systems (GIS), GPR soundings and sedimentological analysis

4Remote sensing as a non- invasive method for study of the past permafrost features. Wielkopolska, Poland case study

Methods for analysis of frost wedge features (1)• Sedimentological analysis

within outcrops

• e.g. Dylik 1966; Goździk 1970, 1973, 1986, 1995, Harry i Goździk 1988; French i Goździk 1988, Kasprzak 1993, 2003

(Kasprzak, 2003)

5Remote sensing as a non- invasive method for study of the past permafrost features. Wielkopolska, Poland case study

Methods for analysis of frost wedge features (2)

• Remote Sensing – analysis of aerial photographs

• e.g. Svenson 1976, 1988; Walters 1978, 1994; Bogdański i Kijowski 1985; Johnson 1990; Kozarski 1995b; Clayton et al. 2001; Ghysels i Heyse 2006

6Remote sensing as a non- invasive method for study of the past permafrost features. Wielkopolska, Poland case study

Methods for analysis of frost wedge features (3)

• Ground Penetrating Radar soundings

• e.g. Munroe et al. 2007; Woodward i Burke 2007; Doolittle i Nelson 2009

(Munroe et al. 2007)

7Remote sensing as a non- invasive method for study of the past permafrost features. Wielkopolska, Poland case study

Case Study - Wielkopolska

• Past permafrost within the Last Glacial Maximum extent (Kozarski 1993, 1995a, 1995b; Kasprzak 2003)

• A few hundred of aerial photographs

• Polygonal structures

8Remote sensing as a non- invasive method for study of the past permafrost features. Wielkopolska, Poland case study

Results of the RS analysis

• Different patterns of structureso Type A – regular polygons with 4 to 8 edges. From a

few to a dozen meters in diameter

o Typ B – irregular polygons with irregular edges. Ussually within slope terrain.

o Typ C - other, non-polygonal structures.

9Remote sensing as a non- invasive method for study of the past permafrost features. Wielkopolska, Poland case study

10Remote sensing as a non- invasive method for study of the past permafrost features. Wielkopolska, Poland case study

III. GPR soundings• Antenna 100 Mhz i 250 Mhz (25 m i 8 m maximum

depth of sounding)

• Data processing - ReflexW5.0

• RTK GPS - location of the cross-lines

11Remote sensing as a non- invasive method for study of the past permafrost features. Wielkopolska, Poland case study

Bytkowo site - antenna 250 MHz

12Remote sensing as a non- invasive method for study of the past permafrost features. Wielkopolska, Poland case study

Bytkowo site - 100 MHz antenna

13Remote sensing as a non- invasive method for study of the past permafrost features. Wielkopolska, Poland case study

Bytkowo – sedimentological analysis

frost-wedge pseudomorphs with primary mineral infilling(sand wedge cast)

14Remote sensing as a non- invasive method for study of the past permafrost features. Wielkopolska, Poland case study

Kiekrz site –structures visible on aerial photographs (Kijowski et al. 2010)Typ C – other, non-polygonal structures

15Remote sensing as a non- invasive method for study of the past permafrost features. Wielkopolska, Poland case study

Kiekrz site – GPR soundings (Kijowski et al. 2010)

16Remote sensing as a non- invasive method for study of the past permafrost features. Wielkopolska, Poland case study

• Remote Sensing – to easily distinguish linear or regular features within the soil cover. This analysis within the GIS framework can be used relatively easily for large and remote areas. 2D image

• GIS analysis – spatial distribution and topology analysis

• GPR soundings – vertical dimension of features. 3D image

• Sedimentological analysis – origin of selected features. Invasive method. Results only for small areas.

Proposed workflow (1)

17Remote sensing as a non- invasive method for study of the past permafrost features. Wielkopolska, Poland case study

Conclusions

• RS and GPR allow the non-invasive analysis of permafrost features, but they need to be verified through direct sedimentological analysis

• To study the distribution of permafrost features RS gives the best results. In lowland settings the best time for photographs is the season with minimal vegetation cover.

• Features founded in Bytkowo can be interpreted as relict sand wedges, whereas those in Kiekrz are of unclear origin .