# How old are Earth’s traces?

Switch between hundreds of millions and tens of thousands of years. Each marker keeps its source’s range and precision and opens the project that documents it.

https://mariuscomper.uk/en/geology/

- [Old Orșova under the Cerna Gulf: 24 metres of water, 5 to 6 metres of mud](https://mariuscomper.uk/orsova-de-sub-lac/en/): Orșova, a town in southwestern Romania, stood at the Cerna’s mouth. A 2017 survey measured the Cerna Gulf to 24 metres deep; a study reports 5 to 6 metres of sediment over the old town site. These are different measurements. In Romanian and English.
- [Sacalin Island between river and sea: what 41 summers of satellite images show](https://mariuscomper.uk/sacalin-insula/en/): Landsat frames from 41 summers, 1984–2025: the distance from a fixed point to the tip of Sacalin Island grew from 6.99 to 10.74 km. In Romanian and English.
- [The Dăbuleni sands, 1984–2025: how a slice of Oltenia's desert turned green and what grows in sand](https://mariuscomper.uk/dabuleni-nisipuri/en/): 41 annual satellite frames, one per summer, over the Dăbuleni sands of southern Romania. The green that stays has grown by 10,540 hectares, from 2,437 to 12,977 — and what never settled into lasting green is, almost everywhere, the water of the Danube.
- [The Living Fire at Lopătari: what burns on the hill and how much gas escapes in a year](https://mariuscomper.uk/focul-viu-lopatari/en/): On a slope in the Buzău Subcarpathians, Romania, gas seeps out of the ground and burns — 21.9–26.9 tonnes of methane a year, by two measurement campaigns. Drill 3,331 metres down after the gas, then set the flame beside your own home's use.
- [Could the Dacian fortresses of the Orăștie Mountains see each other? Computed on the real relief](https://mariuscomper.uk/cetati-care-se-vad/en/): Of 15 pairs, one: Costești-Cetățuie and Blidaru, neighbours 1.6 km apart. In the other 14 the mountain rises at least 100 m above the straight line. From the capital, Sarmizegetusa Regia, none of the other five fortresses can be seen, even from a 12 m tower. A chain of posts in between remains possible; the positions known do not show one.
- [Where people lived when ice covered Europe](https://mariuscomper.uk/europa-sub-gheata/en/): Each light is a Stone Age archaeological site with a radiocarbon date from that time. The ice, the coasts and the lights change as you scroll, from 27,000 years ago to 8,000. Search for your town to see what stood there 21,000 years ago.
- [The last day of the dinosaurs: the Chicxulub asteroid, minute by minute](https://mariuscomper.uk/ultima-zi-a-dinozaurilor/en/): The impact of 66 million years ago on one clock, on the globe as it then was: the shaking, the fragments falling back from the crater, the wave, the years of dark. The rock beneath London was about 6,500 km from the impact; the first tremor reached it after 9 minutes 57 seconds. With the times for 8,771 towns and cities. In Romanian and English.
- [Doggerland map: the land under the North Sea, drowned between 10,000 and 7,000 years ago](https://mariuscomper.uk/drowned-doggerland/): Doggerland joined Britain to Denmark and the Netherlands until the sea drowned it. A relief map of today’s sea floor, with 1,873 river channels, lakes and other features mapped beneath it, and the computed shore of any moment since 16,000 years ago. For each North Sea town, it shows how far away the shore was 10,500 years ago.
- [Kilimanjaro, 5,895 m: the highest mountain in Africa, from its foot to the ice on the summit](https://mariuscomper.uk/kilimanjaro/en/): How high Kilimanjaro is, what it is made of, how much ice it has left and how people climb it: the 5,895 m mountain drawn to scale, with its three cones, seven routes and the ice left since 1912. In Romanian, English and Chinese.
- [Mount Fuji: 3,776 m, the 1707 eruption and the 2026 climbing rules](https://mariuscomper.uk/muntele-fuji/en/): Japan's highest mountain, 3,776 m: its last eruption in 1707–08, Hokusai's print, the four trails and the 2026 climbing rules, with a clock that shows where sunrise finds you. In Romanian, English and Chinese.
- [The height of Everest, 8,848.86 m: the last ten metres, then the whole mountain, drawn to scale](https://mariuscomper.uk/everest/en/): How high Everest is and what the height is measured from: the five published heights from 1856 to 2020 drawn to scale on the last metres of the summit, then the Nepal route, the Tibetan side, the river that lifts the mountain and the sea the metres are counted from. In Romanian, English and Chinese.
- [The 1906 San Francisco earthquake: a city measured by its traces](https://mariuscomper.uk/cutremurul-din-san-francisco-1906/en/): At 5:12 a.m. a foreshock; 20–25 seconds later, Mw 7.9 across 477 km of fault — then three days of fire. Disputed tolls, 478 or over 3,000 dead, the Schmitz handbill and the unbuilt Burnham plan. In Romanian and English.
- [The 1908 Messina earthquake: two cities, an unsettled death toll](https://mariuscomper.uk/cutremurul-din-messina-1908/en/): 05:20 local, Mw 7.10: Messina and Reggio Calabria within minutes, then the tsunami — 3 metres in town, 12–13 metres south of Pellaro. 80,000 estimated dead, the Russian sailors, the shelters and the seismic decree. In Romanian and English.
- [The Green Sahara: lakes, hippos and cattle herders where today there is only sand](https://mariuscomper.uk/sahara-verde/en/): On the shore of a lake in Niger, about 200 graves. Move the clock from 7700 BCE to today and watch the water, the animals and the people go, then watch the rain leave the Sahara on a map: it did not stop everywhere at once.
- [Ice-age footprints at White Sands: someone carried a small child across the mud and walked back](https://mariuscomper.uk/white-sands-footprints/): Two lines of ice-age footprints in New Mexico, at least 1.5 km long, show someone small hurrying across slippery mud with a child probably under three, then walking back hours later. Carry the child along the trail, switch hips, set them down when they wriggle, then walk back over a mammoth’s and a giant sloth’s tracks.
- [Bicaz Gorge: Six, Seven or Eight Kilometres?](https://mariuscomper.uk/cheile-bicazului/en/): Six, seven and a half or eight kilometres of gorge, depending on how you measure. Fly over the real valley, in 3D, and see how the Bicaz river cut the mountain in two: four sectors, walls over three hundred metres, and an incision machine you drive with time. In Romanian and English.
- [The night a lake was born](https://mariuscomper.uk/lacul-rosu/en/): In the summer of 1837, a slope of Mount Ghilcoș slid across the Bicaz valley and created Red Lake, with its drowned fir forest. Replay the night of the slide on the real valley, in 3D, and weigh the evidence: the rains of 1837 or the earthquake of 1838? In Romanian and English.
- [The 1977 earthquake, over today's red-dot buildings](https://mariuscomper.uk/cutremurul-peste-bulina/en/): Follow the 1977 wave across a 3D map of Bucharest, see the damage recorded for each square kilometre and search today's seismic-risk list. The historic record describes map squares, not what happened to any one building.
- [The mine waste that buried a village church. Watch it rise, year by year, from space](https://mariuscomper.uk/geamana/en/): Geamăna, in Romania's Apuseni Mountains, buried since 1978 by the Roșia Poieni copper mine's tailings pond: 48 Landsat photographs, one a year, and terrain measured from orbit show the valley filling up past the church roof. In Romanian and English.
- [The trovants of Costești: do Romania's “growing stones” grow after rain?](https://mariuscomper.uk/trovantii/en/): The round stones of Costești formed underground from sand glued by calcite, and they do not grow after rain: rain only washes the sand from around them. Grow a trovant in a slice of hillside, make it rain and see what changes. Nobody ever measured the “4–5 cm every 1,200 years”. English and Romanian.
- [Did painters paint volcanoes without knowing?](https://mariuscomper.uk/cerul-pictat/en/): 299 sunsets painted between 1500 and 1900, laid side by side into a single sky. How red each one is was measured on the painting. See the sky catch fire after Laki, Tambora and Krakatau, where it doesn't fit, and why Munch's Scream was left out. In Romanian and English.
- [Montjuïc stone: which Barcelona buildings used it](https://mariuscomper.uk/montjuic/en/): The Roman wall, the Cathedral and Gaudí's houses used sandstone from Montjuïc, the hill by the port. The LiDAR relief in 3D, a Roman quarry possibly older than Barcino and, building by building, how the link is known. Under the microscope, two of six Roman carvings "in Montjuïc stone" were another rock. In Romanian, English, Spanish and Catalan.
- [Which mountains you can see from your town: a panorama computed from the terrain for anywhere in Romania](https://mariuscomper.uk/se-vad-muntii/en/): Type a town and see which peaks rise above its horizon and how far away they are. More than half of Romanians live where a peak over 2,000 m would be in view; from the Retezat you can see Bulgaria, from the Apuseni the Tatras.
- [The Mocs meteorite (Mociu, 1882): the stone shower on Koch's map and the 35.70 kg stone](https://mariuscomper.uk/ploaia-de-pietre/en/): On 3 February 1882, after a fireball crossed the sky near Cluj, thousands of stones fell: small ones at one end, giants at the other. Watch them fall again on the map drawn at the time, and weigh the famous “56 kg stone” back into 102 stones. English and Romanian.
- [The Berca mud volcanoes: why they are not volcanoes](https://mariuscomper.uk/vulcanii-care-nu-sunt-vulcani/en/): At Pâclele, cones a few metres high spit cold mud pushed by methane from 3,000 metres down. No magma, no lava. Stand beside a cone, to scale, and see where the ground really burns.
- [The cave bear: the half-tonne giant that ate only plants](https://mariuscomper.uk/ursul-din-pestera/en/): Males weighed 400–500 kilograms and stood, by one press summary, 1.7 metres at the shoulder, and their bones say they ate only plants. Stand next to them, to scale, and see what researchers found in Bears' Cave and three other Romanian caves.
- [The Black Sea has two floors. Nothing downstairs breathes oxygen](https://mariuscomper.uk/marea-neagra-doua-etaje/en/): The top 50 metres hold oxygen. Below 100–150 metres there is none at all, and the oxygen-free water preserves wooden ships for thousands of years. Dive past the ships, down to 2,212 metres.
- [Ciomadul, Romania’s “extinct” volcano, to scale](https://mariuscomper.uk/ultimul-vulcan/en/): Ciomadul last erupted 27,000–32,000 years ago, and “extinct” only means 10,000 quiet years. Put the crater, the lake and your own town on one scale drawing, descend to the partly molten rock and see who says what about the volcano.
- [The cave that lives without the sun](https://mariuscomper.uk/pestera-movile/en/): Under a field near Mangalia, a cave with no natural entrance feeds 52 invertebrate species on sulfur and methane, sealed for 2.5 million years.
- [The night Bucharest fell down](https://mariuscomper.uk/cutremurul-din-1977/en/): 4 March 1977: the ground under Bucharest swayed once every second and a half, close to the beat of the tall interwar blocks. Shake a 1977 street, see the fallen blocks and look up your address on the official seismic-risk list.
- [Oase 1: a Neanderthal ancestor 4–6 generations back](https://mariuscomper.uk/pestera-cu-oase/en/): The remains of a man from about 40,000 years ago, found near Anina: 6–9% Neanderthal DNA from an ancestor 4–6 generations back. The Oase 1 genome, published in 2015.
- [Scărișoara ice cave: ice at least 10,500 years old](https://mariuscomper.uk/ghetarul-de-la-scarisoara/en/): A 1980 guidebook popularised 3,500 years; the 2017 research puts the minimum age at about 10,500. Map, cold trap, chronology.
- [Where was your town 100 million years ago?](https://mariuscomper.uk/unde-era-orasul-tau/en/): Choose a Romanian place and compare the position of the ground beneath it in three published plate-reconstruction models. Differences between the models remain visible.
- [The dinosaurs of Romania: Hațeg Island, to scale](https://mariuscomper.uk/dinozaurii-romaniei/en/): Seventy million years ago Hațeg was an island. A fully grown long-necked dinosaur there weighed under a tonne, and a reptile with 10–12 metre wings flew overhead. Stand next to them, to scale, and see on the map where the bones came from.
- [Romania, 20,000 Years Ago](https://mariuscomper.uk/acum-20000-de-ani/en/): Drag the clock through the last 20,000 years: shoreline, glaciers, steppe and forest, a Danube without a delta, dated human sites and vanished megafauna, with your town pinned.
- [Straight Down · A hundred and thirty-six kilometres under Vrancea](https://mariuscomper.uk/drept-in-jos/en/): Romania's big earthquakes happen between 61 and 184 kilometres below Vrancea. On the map, Bucharest was 4.67 times farther from the 1977 epicentre than Focșani. Through the crust, 1.84 times.
- [A Hundred Times Rarer](https://mariuscomper.uk/craterele-sterse/en/): The Moon has 5,185 confirmed impact craters wider than 20 kilometres. Earth, despite taking more hits per square kilometre, has only 52. An explorer with 70 real craters, from 200 years old to 2.229 billion years old.
- [Romania's Deepest Caves](https://mariuscomper.uk/cele-mai-adanci-pesteri-romania/en/): The Grind shaft leads the ranking by vertical range, at 815 metres. The map and cards track ten caves and shafts, their length, explorers and still-changing records.
- [Where tap water comes from in Romania’s major cities](https://mariuscomper.uk/de-unde-vine-apa/en/): Interactive investigation of drinking water origins across Romania’s 10 major cities: surface reservoirs, karst aquifers, 100+ km aqueducts, hardness, and glass chemistry.
- [Show caves Romania: Ialomita, Polovragi, Comarnic — 2026 fares and hours](https://mariuscomper.uk/pesteri/en/): Three caves with official fares: Ialomita (30 lei, all year), Polovragi (20 lei, daily), Comarnic (35 lei, Apr–Oct, min group 5). Hours and measured drives.
- [Before the S-wave](https://mariuscomper.uk/inainte-de-unda-s/en/): The P–S window matters when the next action was decided beforehand.
- [When Romania's last volcano erupted, people had already reached this land](https://mariuscomper.uk/romania-in-timp/en/): Pick your town and go down beneath it through a core of time: the stones that fell at Mociu, the Scărișoara ice, the cave bear, Ciomadul, the man from Oase, the Paratethys lake, the dinosaur island and where your ground lay 100 million years ago. Every layer, a page from the archive.
- [The mountain with four skins](https://mariuscomper.uk/rosia-montana/en/): Under the quiet valley at Roșia Montană lie four mines, one over another: 7 kilometres of Roman galleries with a trapezoid profile, the centuries of fire and gunpowder, the 400-metre communist quarry — and the pit that was never dug, stopped in the street and in Parliament, tried at Washington. Peel the mountain skin by skin, in schematic 3D.
- [The gorge that swallowed an island](https://mariuscomper.uk/portile-de-fier/en/): At the Cazane narrows the Danube squeezes to some 150 metres and digs some 53 deep: the Roman road with the plaque of year 100, the face of Decebalus carved in 1993–2004, and Ada Kaleh island with its 511 people, drowned by the dam. Raise the water from the Roman level to today's lake, in schematic 3D.
- [The Sphinx and the Babele: Wind or Chisel?](https://mariuscomper.uk/sfinxul-din-bucegi/en/): The Bucegi Sphinx and Babele are erosion remnants in Albian conglomerate, not carvings. A 3D plateau, an erosion machine with a time scale, and five myths set beside the geology — from Ruzo and Cinamar to 28 November.
- [The Growing Delta: Romania's Youngest Land](https://mariuscomper.uk/formarea-deltei/en/): Five thousand years ago this was a Black Sea bay. Fly over the fan, in 3D, and see how the Danube filled it lobe by lobe: three arms, four lobes, old shorelines and a time machine showing the growth — and its braking after the Iron Gates dams. In Romanian and English.
- [Măcin Mountains: Romania's oldest mountains](https://mariuscomper.uk/muntii-macin/en/): Born some three hundred million years ago, before dinosaurs and before the Carpathians, 467 m today. Fly over the 3D relief, climb the eight peaks and rewind time: the Triassic sea, the Cretaceous sea, the emersion. In Romanian and English.
- [The ground under Romania's towns: 26 millimetres a year north-east](https://mariuscomper.uk/orasul-care-se-misca/en/): The ground under every Romanian town moves north-east at about 26 millimetres a year, carried by the Eurasian plate. Relative to the plate little remains, but south of the Carpathians the GPS stations drift coherently south. The station map and your town's number. In Romanian and English.
- [The Carpathians: vanished seas, ice and mountain citadels](https://mariuscomper.uk/arcul-carpatilor/en/): 18 documented places on Carpathian relief, from Hațeg fossils and Miocene salt to the Oase human and Dacian fortresses. Choose two points or towns to see the terrain between them and featured evidence within 30 km of the line.

## Sources

- [International Commission on Stratigraphy · International Chronostratigraphic Chart, v2026/06](https://stratigraphy.org/chart/)
- [International Commission on Stratigraphy · Global Boundary Stratotype Sections and Points](https://stratigraphy.org/gssps/)
- [International Commission on Stratigraphy · International Chronostratigraphic Chart, June 2026 PDF](https://stratigraphy.org/ICSchart/ChronostratChart2026-06.pdf)