Suðurlandsbrotabelti

Seismicity by period · derived statistics from Skjálftalísa (Icelandic Met Office)

Status (automatic)

No particular signs of unrest in the last 24 hours — 11 earthquakes recorded, within the system's normal range.

Transform fracture zone between the Reykjanes belt and the Eastern Volcanic Zone — a plate boundary, not a volcano. Site of South Iceland's largest earthquakes (e.g. 1784, the 2000 South Iceland earthquakes and the 2008 Ölfus M6.3). (overview — more at vedur.is) · circle on the map = rough outline of the system (radius).

📜 Did you know?

The 1784 Skálholt earthquake (M7.1) destroyed Skálholt cathedral and killed three people. This directly caused the abolition of the Skálholt bishopric in 1785 and its transfer to Reykjavík — without this earthquake, Reykjavík might not have become the capital. The first South Iceland earthquake on 17 June 2000 (M6.5) struck on the national holiday; the second (M6.5) on 21 June; the 2008 Ölfus earthquake (M6.3) was the last large one.

Historical eruptions in the system — points colored by size, blue circle shows where we are now in time.

❓ What if a South Iceland earthquake occurs tomorrow?

SISZ is a fracture zone, not a volcano — no eruptions, but the largest earthquakes in southern Iceland. Most likely scenarios: M6.5+ event at 5-10 km depth on a SW-ENE plane. Historically they come in pairs (1784+1789; 2000 17 + 21 June). Impact: Damage to masonry and old buildings in Hveragerði, Selfoss, Hella. Ring Road temporarily closed (cracks, slumps). Bridges over Hvítá and Þjórsá at risk. Fatalities: Historically very low because of low-rise construction (concrete copes well); the 2008 M6.3 caused none. Sources: 2008 Ölfus quake, 2000 South Iceland earthquakes, Páll Einarsson 'Jarðskjálftar á Íslandi'.

This is not a forecast. Based on historical experience and official hazard assessments from the Met Office / Civil Protection.

24 h48 h7 d30 d365 d2 y

Points = earthquake locations in the selected window, coloured by magnitude: M3+ · M2+ · smaller (a sample if more than 800).

Earthquakes

Largest

M0.9

M3,0+

Depth range

0–8 km

Earthquakes over time

Cumulative count · 11 earthquakes · total moment ≈ M1.1 · count moment

Depth (0 km at top). Grey: fixed depth.

Magnitude distribution

Depth cross-sections — color by age (orange=newest, grey=older), point size by M. Rising cluster = possible magma intrusion.

Earthquakes

Largest

M2.0

M3,0+

Depth range

0–15 km

Earthquakes over time

Cumulative count · 19 earthquakes · total moment ≈ M2.1 · count moment

Depth (0 km at top). Grey: fixed depth.

Magnitude distribution

Depth cross-sections — color by age (orange=newest, grey=older), point size by M. Rising cluster = possible magma intrusion.

Earthquakes

Largest

M2.0

M3,0+

Depth range

0–15 km

Earthquakes over time

Cumulative count · 58 earthquakes · total moment ≈ M2.1 · count moment

No significant hypocenter migration — activity is stationary (R²=0.02, n=58); no sign of a propagating dike. Migration shows automatically if R²≥0.30.

Depth (0 km at top). Grey: fixed depth.

Magnitude distribution

Depth cross-sections — color by age (orange=newest, grey=older), point size by M. Rising cluster = possible magma intrusion.

Earthquakes

216

Largest

M2.0

M3,0+

Depth range

0–17 km

Earthquakes over time

Cumulative count · 216 earthquakes · total moment ≈ M2.3 · count moment

Depth (0 km at top). Grey: fixed depth.

Magnitude distribution

Depth cross-sections — color by age (orange=newest, grey=older), point size by M. Rising cluster = possible magma intrusion.

Earthquakes

1794

Largest

M2.6

M3,0+

Depth range

0–35 km

Earthquakes over time

Cumulative count · 1794 earthquakes · total moment ≈ M3.3 · count moment

Depth (0 km at top). Grey: fixed depth.

Magnitude distribution

Depth cross-sections — color by age (orange=newest, grey=older), point size by M. Rising cluster = possible magma intrusion.

Note: before February 2026 about half of events lacked an automatic magnitude, so magnitude-dependent figures (b-value, count of M≥X) under-count earlier periods — the catalogue is not homogeneous across this window. Cumulative moment is barely affected.

Earthquakes

3484

Largest

M2.6

M3,0+

Depth range

0–35 km

Earthquakes over time

Cumulative count · 3484 earthquakes · total moment ≈ M3.4 · count moment

Depth (0 km at top). Grey: fixed depth.

Magnitude distribution

Depth cross-sections — color by age (orange=newest, grey=older), point size by M. Rising cluster = possible magma intrusion.

Depth is automatic and uncertain; earthquakes alone do not show magma movement — deformation (GPS) and gas are needed. Grey points: automatic fixed-depth values. b-value computed for M≥1.5 (automatic magnitudes make lower completeness unreliable). Preliminary data.

Glossary & magnitude scale →

Earthquakes in the system

Time (UTC)	Mag	Depth (km)	Area
2026-07-26 19:26	M0.0	5.2	Other areas
2026-07-26 09:36	M-0.4	8.2	Other areas
2026-07-26 09:36	M0.8	5.1	Other areas
2026-07-26 03:38	M-0.3	0.0	Reykjanesskagi
2026-07-26 03:38	M0.3	7.7	Other areas
2026-07-26 02:26	M0.2	0.1	Other areas
2026-07-26 02:26	M0.2	0.1	Other areas
2026-07-26 02:19	M-0.8	5.2	Other areas
2026-07-26 02:01	M0.9	8.3	Other areas
2026-07-25 23:20	M0.0	5.2	Other areas
2026-07-25 23:20	M-0.8	8.0	Other areas
2026-07-25 05:39	M1.2	0.0	Other areas
2026-07-25 05:33	M1.3	15.0	Other areas
2026-07-25 05:28	M2.0	0.0	Other areas
2026-07-25 04:59	M1.1	0.0	Other areas
2026-07-25 04:12	M0.1	5.2	Other areas
2026-07-25 01:38	M1.5	0.0	Other areas
2026-07-25 00:31	M0.2	7.3	Other areas
2026-07-24 21:53	M0.1	7.3	Other areas
2026-07-24 17:40	M0.4	14.5	Other areas
2026-07-24 12:39	M0.5	1.6	Other areas
2026-07-24 12:30	M0.2	7.4	Other areas
2026-07-24 11:01	M0.3	7.1	Other areas
2026-07-24 10:50	M0.8	7.3	Other areas
2026-07-24 10:49	M0.4	5.2	Other areas
2026-07-24 10:43	M0.2	8.0	Other areas
2026-07-24 10:19	M-0.2	5.2	Other areas
2026-07-24 10:19	M-0.1	5.5	Other areas
2026-07-24 10:13	M1.1	5.9	Other areas
2026-07-24 09:57	M-0.2	5.2	Other areas
2026-07-24 09:55	M0.6	6.0	Other areas
2026-07-24 09:20	M0.6	6.5	Other areas
2026-07-24 03:17	M0.3	0.6	Other areas
2026-07-23 17:43	M0.4	0.0	Other areas
2026-07-23 17:36	M0.2	0.0	Other areas
2026-07-23 14:08	M0.1	0.9	Other areas
2026-07-23 03:34	M0.3	9.3	Reykjanesskagi
2026-07-23 03:34	M1.0	14.9	Other areas
2026-07-22 23:27	M0.3	3.9	Other areas
2026-07-22 19:08	M0.4	1.1	Other areas
2026-07-22 18:07	M0.2	5.9	Other areas
2026-07-22 15:02	M0.4	5.7	Other areas
2026-07-22 04:21	M0.8	6.0	Other areas
2026-07-22 02:02	M0.1	3.1	Other areas
2026-07-22 02:02	M0.1	3.1	Other areas
2026-07-21 23:44	M1.2	5.3	Other areas
2026-07-21 21:43	M0.0	9.2	Other areas
2026-07-21 20:32	M-0.1	7.4	Other areas
2026-07-21 18:04	M0.4	0.0	Other areas
2026-07-21 11:52	M0.1	0.0	Other areas
2026-07-21 01:56	M0.1	6.2	Other areas
2026-07-21 01:50	M0.4	6.1	Other areas
2026-07-21 01:47	M0.9	6.4	Other areas
2026-07-21 01:47	M1.0	4.9	Other areas
2026-07-21 01:18	M-0.4	0.0	Other areas
2026-07-20 22:34	M0.9	0.0	Other areas
2026-07-20 21:33	M0.2	6.5	Other areas
2026-07-20 04:11	M0.0	4.2	Other areas
2026-07-19 16:33	M-0.4	4.3	Reykjanesskagi
2026-07-18 21:59	M-0.4	2.6	Other areas

System journal

Automatic snapshots and media coverage, in chronological order. Subscribe: RSS · ntfy skjalftar-sudurlandsbrotabelti

2026-07-17 00:40:04 UTC

Over the last 24 hours, 15 earthquakes were detected in the South Iceland Seismic Zone, a transform fault zone on a plate boundary where the largest earthquakes in South Iceland occur. This activity is increasing compared to the average of recent weeks, but is still considered within what is normal for this area. The activity consists of scattered background activity rather than swarms, with 73% of events over the last seven days being independent, closely resembling the period around 10 April 2025. The largest earthquake in the last 48 hours was magnitude 1.4 and the total cumulative moment magnitude in the area was 1.6 Mw, although it should be noted that these are automatic preliminary results with unreliable depth estimates.

2026-06-07 00:20:06 UTC

In the last 24 hours, 13 earthquakes were recorded in the South Iceland Seismic Zone, a transverse fault zone and not a volcano. Activity is similar to the past week and considered normal for this area, characterized by distributed background activity rather than swarms, resembling the period around September 14, 2024. The cumulative magnitude over the last 48 hours was Mw 1.3, with the largest event at M0.8. These figures are automatic preliminary results, and further details are available below.

2026-06-05 09:25:07 UTC

In the last 24 hours, 14 earthquakes were recorded in the South Iceland Seismic Zone, which is a transform fault zone and not a volcano. Activity is similar to the past week but slightly higher than usual for this area, characterized by distributed background activity rather than swarms. The largest earthquake was M2.4 and the cumulative magnitude over 48 hours is Mw 2.5; these figures are automatic preliminary results. Current activity most closely resembles the period around September 14, 2024.

2026-06-04 05:10:10 UTC

In the last 24 hours, 19 earthquakes were recorded in the South Iceland Seismic Zone, a transform fault zone and not a volcano, with activity now increasing above the usual rate for this area. The increase is characterized by distributed background activity rather than distinct swarms and most closely resembles the period around May 9, 2025. The cumulative moment over the past 48 hours is Mw 2.5, and the largest earthquake was M2.4. These automatic preliminary results are based solely on measurements, and further data are available below.

2026-06-03 23:35:11 UTC

In the last 24 hours, 17 earthquakes were recorded in the South Iceland Seismic Zone, a transverse fault zone and not a volcano, with activity increasing compared to the weekly average. This increase consists of distributed background seismicity rather than swarms and remains within normal levels for this area. The cumulative magnitude over the past 48 hours was Mw 1.5, and current activity most closely resembles the period around August 12, 2024. Results are automatic preliminary results, and further data can be found below.

2026-06-03 10:30:18 UTC

In the last 24 hours, 19 earthquakes were recorded in the South Iceland Seismic Zone, a transform fault zone and not a volcano, with activity now increasing compared to the weekly average. This increase represents slightly higher than usual activity for the area and is characterized by distributed background seismicity rather than swarms. The largest earthquake in the last 48 hours was M1.6, with a cumulative moment of Mw 1.9 for the period. Results are automatic preliminary data and most closely resemble the period around August 12, 2024.

2026-06-01 21:20:14 UTC

In the last 24 hours, 18 earthquakes were recorded in the South Iceland Seismic Zone, a transverse fault zone and not a volcano, indicating distributed background activity rather than a swarm. Activity is increasing compared to the weekly average but remains within normal levels for this area, most closely resembling the period around November 26, 2025. The cumulative magnitude over the past 48 hours was Mw 1.8, and these results are automatic preliminary data. Further details on trends and maps can be found lower on the page.

2026-05-29 21:07:03 UTC

In the last 24 hours, 10 earthquakes were recorded on the South Iceland Seismic Zone, a transverse fault zone and not a volcano, with activity now increasing and slightly higher than usual for this area. This reflects distributed background activity rather than distinct swarms and is most similar to the period around April 12, 2025. These figures are automatic preliminary results, and further details can be found below.

2026-05-29 11:07:02 UTC

In the last 24 hours, 11 earthquakes were recorded on the South Iceland Seismic Zone, a transform fault zone and not a volcano, with activity now increasing and slightly higher than usual for this area. This increase is characterized by distributed background activity rather than short-lived swarms, with a β-value of 2.4 representing a deviation from the two-year average. The largest earthquake in the last 48 hours was M0.8 with a cumulative moment of Mw 1.3, and these results are automatic preliminary data. Activity most closely resembles the period around June 18, 2024, and further details are available below.

What do the numbers mean — and what should I do?

β (swarm signal): how high activity is versus the area's 2-year average. β above 2 means an ongoing swarm. It measures activity, not a forecast of a large quake.

Cumulative moment (Mw): the combined energy of the quakes in the period. Uplift (GNSS): whether the ground is rising or sinking, mm per year — the data are a few weeks old. Some systems (e.g. Svartsengi) deform in steps during eruption cycles rather than at a steady annual rate.

Swarm character is computed for a whole volcanic belt, not a single system — it describes the belt, not necessarily this one system.

What should I do? This is automatic monitoring for information — not an official warning. Follow official information from the Icelandic Met Office and Civil Protection (112).