1. No category

GTK Airborne Geophysical surveys
Recent examples
Maija Kurimo and Heikki Salmirinne,
GTK Rovaniemi
Kurimo, Salmirinne 6.5.2015
GTK AIRBORNE GEOPHYSICS
1. GTK Airborne Geophysical Mapping project 1972 – 2008
2. Detailed surveys for exploration 2001 - 2008
3. Other airborne data
4. Tendered airborne surveys in Finland by GTK 2008-2013
Kurimo, Salmirinne 6.5.2015
1. GTK Geophysical Mapping Programme Milestones
 1972 programme starts with DC-3 aircraft
 1980 new aircraft DHC Twin Otter
 1993 GPS positionig
 1996 dual-frequency EM system
 2005 four-frequency EM system (together with BGS)
 2007 programme was completed
 2009 the survey equipment was sold out
 2016 old data reprocessing will be completed
Kurimo, Salmirinne 6.5.2015
1. ’Three-in-one’ Mapping Results
Electromagnetic
Kurimo, Salmirinne 6.5.2015
Magnetic
Radiometric
2. Detailed airborne geophysical surveys
Kurimo, Salmirinne 6.5.2015
2. Detailed airborne geophysical surveys
Kurimo, Salmirinne 6.5.2015
2. Detailed airborne geophysical surveys
Target areas were chosen to support GTK exploration
Enhanced line spacing: 50m…75m…100m
High quality postioning, minimizing flight path deviation and altitude
variations
Geological structures had strong influence to survey planning
16 separate areas around Finland, surveyed during 2001-2008
Kurimo, Salmirinne 6.5.2015
2. Detailed airborne geophysical surveys
Levijoki
Kolvakero
Petäjäselkä
Tiukuvaara
Kolari
Sokli
Tulppio
Värriö
Vihanti
Kaustinen
Tipasjärvi
Ullava-Halsua
Kullaa
Vampula
Humppila
Nuutajärvi
Joutseno
Kurimo, Salmirinne 6.5.2015
3. Other data: Koillismaa:
Fugro GEOTEM / Magnetic
Airborne survey 2000
Lines on the geological map
of the Koillismaa area.
1220 km2 area,
line spacing ~300 m.
Kurimo, Salmirinne 6.5.2015
old JV with NAN
4. Tendered airborne surveys in Finland by GTK
Two objectives:
2008
2009
2011
2012
2013
Research and Exploration
Vihanti, Keitele
Hammaslahti
Savukoski
Enontekiö
Outokumpu
Time-domain Electromagnetic (TEM)
Gravity gradiometry
Gravity gradiometry
TEM
Z-Axis Tipper Electromagnetic (ZTEM) survey
Common:
Open tendering according to European Union rules
GTK Quality Control during the survey:
- 1) daily raw data and
- 2) final data
Sometimes interpretation/inversion services included
Continued by GTK own studies, interpretation and evaluation
Kurimo, Salmirinne 6.5.2015
4.1 TEM survey Vihanti and Keitele 2008
Vihanti:
Kurimo, Salmirinne 6.5.2015
* GTK detailed 2-freq EM survey 2004
* Geotech VTEM survey 2008
* GTK 4-frequency EM survey 2008
4.1 TEM survey Vihanti and Keitele 2008
Results:
1) Survey data with technical report
and Geotech interpretation report
2) GTK reports:
VTEM-mittaukset ja vertailu muihin aineistoihin Vihannissa ja Keiteleellä 2008
Maarit Nousiainen (toim.), Hannu Hongisto, Eija Hyvönen, Maija Kurimo, Jarmo Nikander,
Matti Oksama, Aimo Ruotsalainen, Ilkka Suppala, Heikki Vanhala. Q16.1/2008/73
Vihannin ja Keiteleen VTEM-mittausten tutkimukset vuonna 2009
Hanna Leväniemi (toim.), Hannu Hongisto, Taija Huotari-Halkosaari, Jarmo Nikander, Matti
Oksama, Aimo Ruotsalainen, Ilkka Suppala, Heikki Vanhala. Q16.1/2009/65
Kurimo, Salmirinne 6.5.2015
4.2 Gravity gradiometer survey Hammaslahti 2009
First test to compare GTK regional gravity and new airborne gravity:
* quality, resolution, cost
* absolute field vs. gradiometry
Terrain corrected Tz
Kurimo, Salmirinne 6.5.2015
4.2 Gravity gradiometer survey Hammaslahti 2009
Bell Geospace Ltd
FTG survey
(Full Tensor Gradiometer)
Flight lines:
Area A: 960 line_km
line spacing 1000 m
931 km2
Area B+C: 216 line_km
line spacing 500 m
215 km2
PRICE 2745 €
(data + reports delivered by Bell)
Kurimo, Salmirinne 6.5.2015
4.3 Gravity gradiometer survey Savukoski 2011
Fugro, Falcon AGG
Second test of gradiometry vs. regional station survey
Kurimo, Salmirinne 6.5.2015
4.3 Gravity gradiometer survey Savukoski 2011
Savukoski-Pelkosenniemi,
2011
Fugro Airborne Surveys
Falcon AGG
(Airborne Gravity Gradiometer)
Area: 978.5 km2
Line spacing: 500 m
Line direction: EW
Tie line spacing: 5500 m (NS)
Length of lines:
2000.580 km (+ 202 km tie lines)
PRICE 4668 €
(data + reports delivered by Fugro)
Kurimo, Salmirinne 6.5.2015
4.3 Gravity gradiometer survey Savukoski 2011
Salmirinne, H. & Pirttijärvi, M. 2015. Calculation
of the derived Bouguer anomaly
using the equivalent source method based on joint
inversion of ground gravity
and airborne gravity gradient data. Geological Survey
of Finland, Special Paper 57,
185−197, 11 figures.
in
Geological Survey of Finland, Special Paper 57
Novel technologies for greenfield exploration
Edited by Pertti Sarala
Geological Survey of Finland
Espoo
Kurimo, Salmirinne 6.5.2015
4.4 SkyTEM surveys Enontekiö 2012
Area: 212.7 km2
Line intervals: 100 m
Flight direction: E-W
Length of lines: 2136 km
(+ tie lines)
Area: 103.4 km2
Line intervals: 200 m
Flight direction: E-W
Length of lines: 528.0 km
(+ tie lines)
Kurimo, Salmirinne 6.5.2015
4.4 SkyTEM surveys Enontekiö 2012
The equipment setup operates in dual moment configuration including a Low
moment (LM) with a peak moment of ~5000 NIA and a High Moment (HM) with
a peak moment of ~500,000 NIA.
It was agreed to re-fly parts of the survey line
with an alternate system setup
using a base repetition frequency of 12.5 Hz
on High moment only.
Z-component, High moment / gate 21
+ GTK AEM; Real anomalies > 80 ppm
Kurimo, Salmirinne 6.5.2015
4.4 SkyTEM surveys Enontekiö 2012
Results have been utilized in the studies of the area
Pirttijärvi, M. & Salmirinne, H. 2015. ArjunGUI: 2D modelling and inversion
software for airborne time-domain EM data. Geological Survey of Finland, Special
Paper 57, 173−184, 11 figures.
Data, inversions and report
will be available soon
Kurimo, Salmirinne 6.5.2015
4.5 ZTEM survey Outokumpu 2013
Tekes/Green mining:
Developing Mine Camp Exploration Concepts and Technologies
(Brownfield exploration)
Project aims to carry out a methodological and
comparative study on concepts and technologies
for deep exploration (up to 2 km) in the
Outokumpu Belt.
Main geophysical methods are
• reflection seismics (existing HIRE, FIRE),
• deep EM (AMT)
• potential fields (magnetic and gravity)
• petrophysics
• with 3D modeling/inversion
To support the project GTK acquired a Z-Axis
Tipper Electromagnetic (ZTEM) helicopter
survey from Geotech over the area.
Kurimo, Salmirinne 6.5.2015
4.5 ZTEM survey Outokumpu 2013
The project report will be published at the end of
2015.
Kurimo, Salmirinne 6.5.2015
GTK AIRBORNE GEOPHYSICS
GTK Airborne Geophysical Mapping project 1972 – 2008
Detailed surveys for exploration
2001 - 2008
Tendered airborne surveys in Finland
2008 -
Other data
Data available through GTK web : Hakku
or from GTK data service
Kurimo, Salmirinne 6.5.2015
Thank you!
Kurimo, Salmirinne 6.5.2015