earth science

Hecates Tholus

Hecates Tholus is a earth science topic covered in the lgStudy science library. This page brings together a partial reference excerpt, illustrations, worked examples, real-world applications and a short study plan, so you can understand Hecates Tholus rather than just read about it. In short: Hecates Tholus is a Martian volcano, notable for results from the European Space Agency's Mars Express mission which indicate a major eruption took place 350 million years ago. The eruption created a caldera 10 km in diameter on the volcano's western flank.

Key takeaways

Hecates Tholus belongs to earth science; place it in that map before memorising details.
Learn the definition first, then one example that makes the definition concrete.
Connect Hecates Tholus to a quantity you can measure, compute or draw — that is where exam questions come from.
Reproduce the core statement of Hecates Tholus from memory before moving on to harder problems.

Reference excerpt

Hecates Tholus is a Martian volcano, notable for results from the European Space Agency's Mars Express mission which indicate a major eruption took place 350 million years ago. The eruption created a caldera 10 km in diameter on the volcano's western flank. The volcano is at location 32.12°N 150.24°E, in the volcanic province Elysium, and has a diameter of 182 km. It is the northernmost of the Elysium volcanoes; the others are Elysium Mons and Albor Tholus. Hecates Tholus is in the Cebrenia quadrangle.

Origin of name In planetary nomenclature, a "tholus" is a "small domical mountain or hill". Hecates is named after Hecate, the goddess of the ghost-world, nightly events, and sorcery.

Observation history Hecates Tholus was first named in 1973. In 2004, ESA's High Resolution Stereo Camera and NASA's Thermal Emission Imaging System both took pictures of the region from orbit. These observations showed that this region was more complex than previously assumed, and multiple papers were published using the new data.

Formation The eruption which formed the caldera of Hecates Tholus took place 350 million years ago. However, the volcano itself dates back to the Hesperian period of Mars's history, and is at least 3.8 billion years old. Volcanic activity lasted until at least 335 million years ago, and potentially as recent as 100 million years ago. There are at least 5 concentric calderas at the summit; there is some disagreement about the ages of the calderas, most notably the fourth and fifth calderas for which age estimations differ by a factor of ten when one chooses whether or not to factor external lava flows into the age estimation process. It has been suggested that glacial deposits later partly filled the caldera and an adjacent depression. Crater counts indicate this happened as recently as 5 to 20 million years ago, and potentially as recently as 440,000 years ago. Glacial events have been occurring since as far back as 1.4 billion years ago. The valleys of Hecates Tholus are expected to have been formed by meltwater from these glaciers. However climate models show that ice is not stable at Hecates Tholus today, pointing to climate change since the glaciers were active. It has been shown that the age of the glaciers correspond to a period of increased obliquity of Mars's rotational axis. The western flank is expected to have been resurfaced in the Late Amazonian period, due to its lack of craters relative to the rest of the volcano. While craters are useful in dating Martian volcanos, it has proven difficult to apply this method too Hecates Tholus.

Gallery

See also Climate of Mars Geography of Mars Geology of Mars HiRISE List of mountains on Mars by height Volcanoes on Mars Volcanology of Mars

References

External links Google Mars - zoomable map centered on Hecates Tholus "Hecates Tholus". Gazetteer of Planetary Nomenclature. USGS Astrogeology Research Program. 3-D view of Hecates Tholus from Mars Express

Illustrations

Worked examples

Example 1 — a first encounter with Hecates Tholus

Start with the simplest possible case. Write down what Hecates Tholus claims or describes in one sentence, then invent the smallest concrete situation in which that sentence is true. In earth science, the smallest case is usually a single object, a single equation or a single measurement. Check that every symbol or term in your sentence has a meaning in that case.

Example 2 — changing one variable

Take the situation from Example 1 and change exactly one quantity: double it, halve it, or set it to zero. Predict what should happen to Hecates Tholus before you calculate. Comparing your prediction with the result is the fastest way to find out whether you understand the idea or only the words.

Example 3 — an exam-style question

Typical questions about Hecates Tholus ask you to (a) state it precisely, (b) apply it to given data, and (c) explain a limitation. Practise writing all three answers in under five minutes; the third part is what separates a full-mark answer from an average one.

Applications of Hecates Tholus

In research: Hecates Tholus appears in earth science research whenever the underlying quantities have to be modelled precisely. Papers usually cite it as a starting assumption and then explore where it breaks down.
In technology and industry: Engineering practice reuses Hecates Tholus in design rules, simulations and safety margins. Knowing the idea lets you read a specification sheet and understand why the numbers look the way they do.
In the classroom: Hecates Tholus is common in secondary-school and first-year university syllabi. It links to neighbouring topics Cebrenia quadrangle, Hecate, Mountains on Mars, so understanding it makes those chapters shorter.
In everyday life: Look for Hecates Tholus outside the textbook — in sport, cooking, traffic, electronics or the sky above you. An example you found yourself is remembered far longer than one you were given.

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How to study Hecates Tholus in 20 minutes

Read the reference excerpt below once, without taking notes.
Close the page and write down what Hecates Tholus means in your own words.
Compare your version with the excerpt and mark what you missed.
Work through the three examples above with pen and paper.
Explain Hecates Tholus out loud to somebody else — or to Teacher Smith in the lgStudy chat.

Frequently asked questions

What is Hecates Tholus in simple terms?

Why does Hecates Tholus matter?

Because it connects several earth science ideas at once: it gives you a definition you can apply, a quantity you can calculate, and a way to check whether a result is plausible.

How should I study Hecates Tholus?

Read the excerpt, restate it from memory, then work through the examples and applications listed on this page. The five-step study plan above takes about twenty minutes.

What does this page cover?

It gives you a compact reference excerpt plus original lgStudy explanations, examples, applications and study material on Hecates Tholus.