Innovation: Rich prospects by satellite snap: Mining groups are using images from space to seek out resources throughout the world

MINERAL deposits used to be found by chance or mistake - oil seeping from the ground, grains of gold in a stream, a misbehaving compass. In this century, exploration has been helped along by technology - test drilling, sophisticated sample analysis and aerial photographs. Today, mining companies are increasingly turning to satellite - the ultimate spy-in-the-sky that lets them examine the most remote corners of the Earth from the comfort of a laboratory.

At the same time, political changes have made exploration more worthwhile. As recently as five years ago, there were still dozens of countries in Africa, Asia, South America and Eastern Europe where a mining company would not have been welcome. But with the sweeping shift towards liberalisation, most governments are now happy to encourage foreigners who will help them exploit their wealth of resources. As a result, the big mining groups are pouring funds into exploration - hoping to find the kind of large reserves that will generate profits even when prices are low.

RTZ, the world's biggest mining group, has expanded exploration rapidly since it bought BP Minerals in 1989. Its US and Australian operations have their own dedicated departments, its South American exploration is covered from Santiago, Chile, and it monitors the rest of the world from a small office in the centre of Newbury, Berkshire.

Here, Alastair Lamb, the geologist in charge of satellite exploration, and a colleague pore over images - either on paper or a computer screen. Some show known mining areas where bodies of ore may still lie undiscovered. Others are used for 'grassroots exploration' - of areas where no minerals have been found but where the geology looks promising.

Mr Lamb pulls out a print, about three feet square, showing 185 square kilometres of mountainous country in Central America. Taken from an altitude of 720km, it was produced from 270 megabytes of computer data generated by an 'imaging device' on the US Landsat satellite. It cost dollars 4,400 (pounds 3,060).

He points to a semicircle marking out a caldera, the top of an extinct volcano, and explains that ores are most likely to give themselves away in fractured volcanic structures.

Physical analysis can help geologists, but the real strength of the satellite shows up when the data is used to enhance 'spectral bands' that highlight particular types of material on the Earth's surface. Another version of the same image exaggerates areas rich in iron oxide and clay. A yellowing indicates that both exist.

Certain minerals will attack the surrounding rock, causing a staining or 'haloing' effect that can be seen from space. When an interesting formation shows up, someone will be sent in by car or helicopter to take samples. 'Often he will find scratchings in the hillside from the last century,' Mr Lamb said.

If the area is promising, the company will stake a claim and start the process that may eventually lead to a mine.

Satellite pictures have been available for 21 years, since the first Landsat was launched. Initially, however, resolution was not good enough for minerals. Landsat 4 went up in 1982 with a 'thematic mapper' instrument that could break down the information by spectral band, and it was much more effective. Landsat 5, launched in 1985, is to be replaced later this year. The French have a satellite called SPOT, which has better spatial, but not spectral, resolution than Landsat.

The satellites take two hours to circle the Earth over the poles, and the whole surface is covered in 16 days. That does not mean the whole world can be examined, however, because coverage depends on ground stations that can pick up and retransmit the signals; the gaps are being filled, but there are still areas on which there is no data.

Satellites have limitations. For instance, they cannot normally see through clouds or trees, which is why the minerals of much of the world (including Eastern Europe) remain out of sight. Their cameras also get confused by vegetation.

Remote sensing is at its most effective in arid areas with young volcanic rocks, such as the south-western US, where the technology was developed. The Andes are also suitable, and mining companies are particularly active in Chile, where the political climate is favourable to them.

Remote sensing has also paid off in Burundi, Central Africa, where Landsat pictures showed that the geological structure was quite different from what had previously been assumed. SPOT data has also been used to find gold in the Altai Mountains of China.

Although satellite data will undoubtedly improve, Mr Lamb said mining companies could not afford to wait. There was, he claimed, a window of opportunity for finding many world-class deposits during this decade.

(Photographs omitted)

Suggested Topics
News
people
News
people And here is why...
News
peopleStella McCartney apologises over controversial Instagram picture
Life and Style
Laid bare: the Good2Go app ensures people have a chance to make their intentions clear about having sex
techCould Good2Go end disputes about sexual consent - without being a passion-killer?
PROMOTED VIDEO
Arts and Entertainment
Richard Burr remains the baker to beat on the Great British Bake Off
tvRichard remains the baker to beat as Chetna begins to flake
News
i100
Sport
footballArsenal 4 Galatasaray 1: Wenger celebrates 18th anniversary in style
Arts and Entertainment
Amazon has added a cautionary warning to Tom and Jerry cartoons on its streaming service
tv
News
people
News
The village was originally named Llansanffraid-ym-Mechain after the Celtic female Saint Brigit, but the name was changed 150 years ago to Llansantffraid – a decision which suggests the incorrect gender of the saint
newsWelsh town changes its name, but can you spot the difference?
News
ebooksAn unforgettable anthology of contemporary reportage
Arts and Entertainment
Kristen Scott Thomas in Electra at the Old Vic
theatreReview: Kristin Scott Thomas is magnificent in a five-star performance of ‘Electra’
News
Destructive discourse: Jewish boys look at anti-Semitic graffiti sprayed on to the walls of the synagogue in March 2006, near Tel Aviv
peopleAt the start of Yom Kippur and with anti-Semitism flourishing, one Jew can no longer ignore his identity
Life and Style
Couples who boast about their relationship have been condemned as the most annoying Facebook users
tech
Arts and Entertainment
Hayley Williams performs with Paramore in New York
musicParamore singer says 'Steal Your Girl' is itself stolen from a New Found Glory hit
News
i100
Latest stories from i100
Have you tried new the Independent Digital Edition apps?
Independent Dating
and  

By clicking 'Search' you
are agreeing to our
Terms of Use.

iJobs Job Widget
iJobs Money & Business

Trainee Recruitment Consultant - Birmingham - Real Staffing

£18000 - £23000 per annum + Commission: SThree: Real Staffing are currently lo...

Trust Accountant - Kent

NEGOTIABLE: Austen Lloyd: TRUST ACCOUNTANT - KENTIf you are a Chartered Accou...

Graduate Recruitment Consultant - 2013/14 Grads - No Exp Needed

£18000 - £20000 per annum + OTE £30000: SThree: SThree are a global FTSE 250 b...

Law Costs

Highly Competitive Salary: Austen Lloyd: CITY - Law Costs Draftsperson - NICHE...

Day In a Page

Italian couples fake UK divorce scam on an ‘industrial scale’

Welcome to Maidenhead, the divorce capital of... Italy

A look at the the legal tourists who exploited our liberal dissolution rules
Time to stop running: At the start of Yom Kippur and with anti-Semitism flourishing, one Jew can no longer ignore his identity

Time to stop running

At the start of Yom Kippur and with anti-Semitism flourishing, one Jew can no longer ignore his identity
Tom and Jerry cartoons now carry a 'racial prejudice' warning on Amazon

Tom and Jerry cartoons now carry a 'racial prejudice' warning on Amazon

The vintage series has often been criticised for racial stereotyping
An app for the amorous: Could Good2Go end disputes about sexual consent - without being a passion-killer?

An app for the amorous

Could Good2Go end disputes about sexual consent - without being a passion-killer?
Llansanffraid is now Llansantffraid. Welsh town changes its name, but can you spot the difference?

Llansanffraid is now Llansantffraid

Welsh town changes its name, but can you spot the difference?
Charlotte Riley: At the peak of her powers

Charlotte Riley: At the peak of her powers

After a few early missteps with Chekhov, her acting career has taken her to Hollywood. Next up is a role in the BBC’s gangster drama ‘Peaky Blinders’
She's having a laugh: Britain's female comedians have never had it so good

She's having a laugh

Britain's female comedians have never had it so good, says stand-up Natalie Haynes
Sistine Chapel to ‘sing’ with new LED lights designed to bring Michelangelo’s masterpiece out of the shadows

Let there be light

Sistine Chapel to ‘sing’ with new LEDs designed to bring Michelangelo’s masterpiece out of the shadows
Great British Bake Off, semi-final, review: Richard remains the baker to beat

Tensions rise in Bake Off's pastry week

Richard remains the baker to beat as Chetna begins to flake
Paris Fashion Week, spring/summer 2015: Time travel fashion at Louis Vuitton in Paris

A look to the future

It's time travel fashion at Louis Vuitton in Paris
The 10 best bedspreads

The 10 best bedspreads

Before you up the tog count on your duvet, add an extra layer and a room-changing piece to your bed this autumn
Arsenal vs Galatasaray: Five things we learnt from the Emirates

Arsenal vs Galatasaray

Five things we learnt from the Gunners' Champions League victory at the Emirates
Stuart Lancaster’s long-term deal makes sense – a rarity for a decision taken by the RFU

Lancaster’s long-term deal makes sense – a rarity for a decision taken by the RFU

This deal gives England a head-start to prepare for 2019 World Cup, says Chris Hewett
Ebola outbreak: The children orphaned by the virus – then rejected by surviving relatives over fear of infection

The children orphaned by Ebola...

... then rejected by surviving relatives over fear of infection
Pride: Are censors pandering to homophobia?

Are censors pandering to homophobia?

US film censors have ruled 'Pride' unfit for under-16s, though it contains no sex or violence